Quarterly report pursuant to Section 13 or 15(d)

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

v3.4.0.3
Securities - Summary of Investment Securities Available for Sale (Detail) - USD ($)
$ in Thousands
Mar. 31, 2016
Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost $ 667,640 $ 700,627
Gross Unrealized Gain 8,390 2,488
Gross Unrealized Loss 998 4,819
Estimated Fair Value 675,032 698,296
Municipal bonds-tax exempt [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 161,527 162,101
Gross Unrealized Gain 4,599 1,820
Gross Unrealized Loss 0 19
Estimated Fair Value 166,126 163,902
Municipal bonds-taxable [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 13,888 13,932
Gross Unrealized Gain 425 189
Gross Unrealized Loss 0 88
Estimated Fair Value 14,313 14,033
Corporate bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 5,016 5,017
Gross Unrealized Gain 0 0
Gross Unrealized Loss 18 24
Estimated Fair Value 4,998 4,993
Mutual funds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 22,916 22,916
Gross Unrealized Gain 240 0
Gross Unrealized Loss 87 163
Estimated Fair Value 23,069 22,753
Collateralized mortgage obligations [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 91,947 97,904
Gross Unrealized Gain 404 79
Gross Unrealized Loss 222 997
Estimated Fair Value 92,129 96,986
Mortgage-backed securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 271,395 286,450
Gross Unrealized Gain 2,642 392
Gross Unrealized Loss 447 2,461
Estimated Fair Value 273,590 284,381
U.S. government agency securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 39,982 48,478
Gross Unrealized Gain 66 0
Gross Unrealized Loss 8 656
Estimated Fair Value 40,040 47,822
SBA loan pool securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 60,811 63,670
Gross Unrealized Gain 12 7
Gross Unrealized Loss 216 411
Estimated Fair Value 60,607 63,266
U.S. treasury securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Amortized Cost 158 159
Gross Unrealized Gain 2 1
Gross Unrealized Loss 0 0
Estimated Fair Value 160 160
Collateralized home equity conversion mortgages [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Estimated Fair Value $ 56,900 $ 58,600