Accumulated Other Comprehensive Income (Loss) - Summary of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 52,826	$ 67,794	$ 77,262
Balances after cumulative effects				$ 52,826
Other comprehensive income (loss)	(1,770)	717	(1,262)
Balance at end of period	42,163	52,826	67,794
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(363)	(1,080)	182
Balances after cumulative effects	(842)			(842)
Other comprehensive income (loss) before reclassifications	(1,825)	795
Less: amounts reclassified from accumulated other comprehensive income (loss)	(55)	78
Other comprehensive income (loss)	(1,770)	717	(1,262)
Balance at end of period	$ (2,612)	$ (363)	$ (1,080)
Accounting Standards Update 2016-01 | Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative effect of adoption of ASU				(556)
Accounting Standards Update 2018-02 | Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative effect of adoption of ASU				$ 77