Quarterly report pursuant to Section 13 or 15(d)

Off-Balance Sheet Commitments - Distribution of Undisbursed Loan Commitments (Detail)

v3.5.0.2
Off-Balance Sheet Commitments - Distribution of Undisbursed Loan Commitments (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Dec. 31, 2015
Loss Contingencies [Line Items]          
Total undisbursed loan commitments $ 286,066   $ 286,066   $ 273,537
Allowance for Loan Off-Balance Sheet Items [Roll Forward]          
Balance at beginning of period     42,935    
(Negative provision) provision (1,515) $ (2,403) (3,040) $ (4,076)  
Balance at end of period 39,707   39,707    
Non-PCI Loans [Member]          
Allowance for Loan Off-Balance Sheet Items [Roll Forward]          
Balance at beginning of period 35,381 51,515 37,494 51,640  
(Negative provision) provision (1,455) (2,619) (3,184) (4,402)  
Balance at end of period 34,259 49,468 34,259 49,468  
Allowance for off-balance sheet items [Member]          
Allowance for Loan Off-Balance Sheet Items [Roll Forward]          
Balance at beginning of period   1,054      
(Negative provision) provision   (92)      
Balance at end of period   962   962  
Allowance for off-balance sheet items [Member] | Non-PCI Loans [Member]          
Allowance for Loan Off-Balance Sheet Items [Roll Forward]          
Balance at beginning of period 1,220   986 1,366  
(Negative provision) provision 255   489 (404)  
Balance at end of period 1,475 $ 962 1,475 $ 962  
Commitments to extend credit [Member]          
Loss Contingencies [Line Items]          
Total undisbursed loan commitments 272,884   272,884   262,680
Standby letters of credit [Member]          
Loss Contingencies [Line Items]          
Total undisbursed loan commitments 7,658   7,658   6,839
Commercial letters of credit [Member]          
Loss Contingencies [Line Items]          
Total undisbursed loan commitments $ 5,524   $ 5,524   $ 4,018