Quarterly report pursuant to Section 13 or 15(d)

Securities - Summary of Investment Securities Available for Sale (Detail)

v3.5.0.2
Securities - Summary of Investment Securities Available for Sale (Detail) - USD ($)
$ in Thousands
Jun. 30, 2016
Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost $ 622,459 $ 700,627
Gross Unrealized Gain 14,272 2,488
Gross Unrealized Loss 456 4,819
Estimated Fair Value 636,275 698,296
Municipal bonds-tax exempt [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 160,951 162,101
Gross Unrealized Gain 8,475 1,820
Gross Unrealized Loss 0 19
Estimated Fair Value 169,426 163,902
Municipal bonds-taxable [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 13,476 13,932
Gross Unrealized Gain 616 189
Gross Unrealized Loss 0 88
Estimated Fair Value 14,092 14,033
Corporate bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 5,014 5,017
Gross Unrealized Gain 0 0
Gross Unrealized Loss 13 24
Estimated Fair Value 5,001 4,993
Mutual funds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 22,916 22,916
Gross Unrealized Gain 382 0
Gross Unrealized Loss 85 163
Estimated Fair Value 23,213 22,753
Collateralized mortgage obligations [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 85,678 97,904
Gross Unrealized Gain 554 79
Gross Unrealized Loss 91 997
Estimated Fair Value 86,141 96,986
Mortgage-backed securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 262,223 286,450
Gross Unrealized Gain 4,129 392
Gross Unrealized Loss 77 2,461
Estimated Fair Value 266,275 284,381
U.S. government agency securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 15,491 48,478
Gross Unrealized Gain 53 0
Gross Unrealized Loss 0 656
Estimated Fair Value 15,544 47,822
SBA loan pool securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 56,553 63,670
Gross Unrealized Gain 62 7
Gross Unrealized Loss 190 411
Estimated Fair Value 56,425 63,266
U.S. treasury securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 157 159
Gross Unrealized Gain 1 1
Gross Unrealized Loss 0 0
Estimated Fair Value 158 160
Collateralized home equity conversion mortgages [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Estimated Fair Value $ 55,700 $ 58,600