Annual report pursuant to Section 13 and 15(d)

Loans - Analysis of Gross Loans, Disaggregated by Loan Class (Detail)

v3.3.1.900
Loans - Analysis of Gross Loans, Disaggregated by Loan Class (Detail) - USD ($)
$ in Thousands
Dec. 31, 2015
Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans $ 3,183,316 $ 2,788,498
Accruing 90 Days or More Past Due 0 0
Real estate loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans 2,845,514 2,511,429
Real estate loans [Member] | Hotel/motel [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans 543,425 462,718
Real estate loans [Member] | Gas station [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans 323,655 370,416
Real estate loans [Member] | Construction [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans 23,387 9,527
Real estate loans [Member] | Residential property [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans 236,036 135,462
Commercial and industrial loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans 312,876 249,480
Commercial and industrial loans [Member] | Commercial term [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans 152,773 116,536
Commercial and industrial loans [Member] | Commercial lines of credit [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans 128,224 93,970
Commercial and industrial loans [Member] | International loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans 31,879 38,974
Consumer loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans 24,926 27,589
30-59 Days Past Due [Member] | Commercial and industrial loans [Member] | International loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 0  
Non-PCI Loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 15,374 24,299
Current 3,147,928 2,716,461
Total loans 3,163,302 2,740,760
Accruing 90 Days or More Past Due 0 0
Non-PCI Loans [Member] | Real estate loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans 2,825,718  
Non-PCI Loans [Member] | Real estate loans [Member] | Retail [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 1,183 3,755
Current 734,318 671,317
Total loans 735,501 675,072
Accruing 90 Days or More Past Due 0 0
Non-PCI Loans [Member] | Real estate loans [Member] | Hotel/motel [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 5,139 4,304
Current 534,206 450,195
Total loans 539,345 454,499
Accruing 90 Days or More Past Due 0 0
Non-PCI Loans [Member] | Real estate loans [Member] | Gas station [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 2,882 4,457
Current 316,481 357,783
Total loans 319,363 362,240
Accruing 90 Days or More Past Due 0 0
Non-PCI Loans [Member] | Real estate loans [Member] | Other [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 3,441 4,972
Current 969,802 837,154
Total loans 973,243 842,126
Accruing 90 Days or More Past Due 0 0
Non-PCI Loans [Member] | Real estate loans [Member] | Construction [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 0 0
Current 23,387 9,517
Total loans 23,387 9,517
Accruing 90 Days or More Past Due 0 0
Non-PCI Loans [Member] | Real estate loans [Member] | Residential property [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 396 854
Current 234,483 120,078
Total loans 234,879 120,932
Accruing 90 Days or More Past Due 0 0
Non-PCI Loans [Member] | Commercial and industrial loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total loans 312,705  
Non-PCI Loans [Member] | Commercial and industrial loans [Member] | Commercial term [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 1,131 4,444
Current 151,471 111,629
Total loans 152,602 116,073
Accruing 90 Days or More Past Due 0 0
Non-PCI Loans [Member] | Commercial and industrial loans [Member] | Commercial lines of credit [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 450 227
Current 127,774 93,633
Total loans 128,224 93,860
Accruing 90 Days or More Past Due 0 0
Non-PCI Loans [Member] | Commercial and industrial loans [Member] | International loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 497 200
Current 31,382 38,729
Total loans 31,879 38,929
Accruing 90 Days or More Past Due 0 0
Non-PCI Loans [Member] | Consumer loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 255 1,086
Current 24,624 26,426
Total loans 24,879 27,512
Accruing 90 Days or More Past Due 0 0
Non-PCI Loans [Member] | 30-59 Days Past Due [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 4,522 9,713
Non-PCI Loans [Member] | 30-59 Days Past Due [Member] | Real estate loans [Member] | Retail [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 441 1,554
Non-PCI Loans [Member] | 30-59 Days Past Due [Member] | Real estate loans [Member] | Hotel/motel [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 1,250 1,531
Non-PCI Loans [Member] | 30-59 Days Past Due [Member] | Real estate loans [Member] | Gas station [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 959 2,991
Non-PCI Loans [Member] | 30-59 Days Past Due [Member] | Real estate loans [Member] | Other [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 1,144 1,674
Non-PCI Loans [Member] | 30-59 Days Past Due [Member] | Real estate loans [Member] | Construction [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 0 0
Non-PCI Loans [Member] | 30-59 Days Past Due [Member] | Real estate loans [Member] | Residential property [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 0 167
Non-PCI Loans [Member] | 30-59 Days Past Due [Member] | Commercial and industrial loans [Member] | Commercial term [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 420 1,107
Non-PCI Loans [Member] | 30-59 Days Past Due [Member] | Commercial and industrial loans [Member] | Commercial lines of credit [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 58 0
Non-PCI Loans [Member] | 30-59 Days Past Due [Member] | Commercial and industrial loans [Member] | International loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable   200
Non-PCI Loans [Member] | 30-59 Days Past Due [Member] | Consumer loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 250 489
Non-PCI Loans [Member] | 60-89 Days Past Due [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 2,214 6,729
Non-PCI Loans [Member] | 60-89 Days Past Due [Member] | Real estate loans [Member] | Retail [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 343 281
Non-PCI Loans [Member] | 60-89 Days Past Due [Member] | Real estate loans [Member] | Hotel/motel [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 49 2,340
Non-PCI Loans [Member] | 60-89 Days Past Due [Member] | Real estate loans [Member] | Gas station [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 406 1,113
Non-PCI Loans [Member] | 60-89 Days Past Due [Member] | Real estate loans [Member] | Other [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 661 2,156
Non-PCI Loans [Member] | 60-89 Days Past Due [Member] | Real estate loans [Member] | Construction [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 0 0
Non-PCI Loans [Member] | 60-89 Days Past Due [Member] | Real estate loans [Member] | Residential property [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 0 0
Non-PCI Loans [Member] | 60-89 Days Past Due [Member] | Commercial and industrial loans [Member] | Commercial term [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 253 490
Non-PCI Loans [Member] | 60-89 Days Past Due [Member] | Commercial and industrial loans [Member] | Commercial lines of credit [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 0 0
Non-PCI Loans [Member] | 60-89 Days Past Due [Member] | Commercial and industrial loans [Member] | International loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 497 0
Non-PCI Loans [Member] | 60-89 Days Past Due [Member] | Consumer loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 5 349
Non-PCI Loans [Member] | 90 Days or More Past Due [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 8,638 7,857
Non-PCI Loans [Member] | 90 Days or More Past Due [Member] | Real estate loans [Member] | Retail [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 399 1,920
Non-PCI Loans [Member] | 90 Days or More Past Due [Member] | Real estate loans [Member] | Hotel/motel [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 3,840 433
Non-PCI Loans [Member] | 90 Days or More Past Due [Member] | Real estate loans [Member] | Gas station [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 1,517 353
Non-PCI Loans [Member] | 90 Days or More Past Due [Member] | Real estate loans [Member] | Other [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 1,636 1,142
Non-PCI Loans [Member] | 90 Days or More Past Due [Member] | Real estate loans [Member] | Construction [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 0 0
Non-PCI Loans [Member] | 90 Days or More Past Due [Member] | Real estate loans [Member] | Residential property [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 396 687
Non-PCI Loans [Member] | 90 Days or More Past Due [Member] | Commercial and industrial loans [Member] | Commercial term [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 458 2,847
Non-PCI Loans [Member] | 90 Days or More Past Due [Member] | Commercial and industrial loans [Member] | Commercial lines of credit [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 392 227
Non-PCI Loans [Member] | 90 Days or More Past Due [Member] | Commercial and industrial loans [Member] | International loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable 0 0
Non-PCI Loans [Member] | 90 Days or More Past Due [Member] | Consumer loans [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Past due loans receivable $ 0 $ 248