Annual report pursuant to Section 13 and 15(d)

Accumulated Other Comprehensive Income (Loss) - Activity in Accumulated Other Comprehensive Income (Detail)

v3.10.0.1
Accumulated Other Comprehensive Income (Loss) - Activity in Accumulated Other Comprehensive Income (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]      
Balance at beginning of period, before tax $ (3,188) $ (4,089)  
Balance at end of period, before tax (8,536) (3,188) $ (4,089)
Adjustments to accumulated other comprehensive income, tax (546)    
Beginning balance 562,477 531,025 493,918
Other comprehensive loss before reclassification (4,106) 2,273 (2,033)
Reclassification from accumulated other comprehensive loss (87) (1,748) (46)
Adjustments to accumulated other comprehensive income (17)    
Other comprehensive (loss) income (4,210) 525 (2,079)
Ending balance 552,568 562,477 531,025
Unrealized Gains and Losses on Interest-Only Strip      
AOCI Attributable to Parent, Net of Tax [Roll Forward]      
Balance at beginning of period, before tax 0 0  
Balance at end of period, before tax 0 0 0
Unrealized Gains and Losses on Available-for-Sale Securities      
AOCI Attributable to Parent, Net of Tax [Roll Forward]      
Balance at beginning of period, before tax (3,188) (4,089) (2,331)
Other comprehensive loss before reclassification, before tax (5,790) 2,649 (1,712)
Reclassification from accumulated other comprehensive loss, before tax (87) (1,748) (46)
Adjustments to accumulated other comprehensive income, before tax 529    
Period change, before tax (5,348) 901 (1,758)
Balance at end of period, before tax   (3,188) (4,089)
Unrealized Gains and Losses on Available-for-Sale Securities | Unrealized Gains and Losses on Interest-Only Strip      
AOCI Attributable to Parent, Net of Tax [Roll Forward]      
Balance at beginning of period, before tax 0 0 9
Other comprehensive loss before reclassification, before tax 0 0 (9)
Reclassification from accumulated other comprehensive loss, before tax 0 0 0
Adjustments to accumulated other comprehensive income, before tax 0    
Period change, before tax 0 0 (9)
Balance at end of period, before tax   0 0
Tax Benefit (Expense)      
AOCI Attributable to Parent, Net of Tax [Roll Forward]      
Balance at beginning of period, tax 1,319 1,695 2,007
Other comprehensive loss before reclassification, tax 1,684 (376) (312)
Reclassification from accumulated other comprehensive loss, tax 0 0 0
Period change, tax 1,138 (376) (312)
Balance at end of period, tax 2,457 1,319 1,695
Accumulated Other Comprehensive Income (Loss)      
AOCI Attributable to Parent, Net of Tax [Roll Forward]      
Beginning balance (1,869) (2,394) (315)
Ending balance $ (6,079) $ (1,869) $ (2,394)