Annual report pursuant to Section 13 and 15(d)

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

v3.10.0.1
Securities - Summary of Investment Securities Available for Sale (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost $ 583,444 $ 581,992
Gross Unrealized Gain 401 2,096
Gross Unrealized Loss 8,937 5,284
Estimated Fair Value 574,908 578,804
Mortgage-backed securities    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 300,957 306,166
Gross Unrealized Gain 61 145
Gross Unrealized Loss 5,984 2,702
Estimated Fair Value 295,034 303,609
Collateralized mortgage obligations    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 124,550 119,658
Gross Unrealized Gain 74 8
Gross Unrealized Loss 2,332 1,898
Estimated Fair Value 122,292 117,768
U.S. government agency securities    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 7,499 7,499
Gross Unrealized Gain 0 0
Gross Unrealized Loss 97 85
Estimated Fair Value 7,402 7,414
Municipal bonds-tax exempt    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 110,670 125,601
Gross Unrealized Gain 197 1,943
Gross Unrealized Loss 517 69
Estimated Fair Value 110,350 127,475
U.S. treasury securities    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 39,768 152
Gross Unrealized Gain 69 0
Gross Unrealized Loss 7 0
Estimated Fair Value $ 39,830 152
Mutual funds    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost   22,916
Gross Unrealized Gain   0
Gross Unrealized Loss   530
Estimated Fair Value   $ 22,386