Accumulated Other Comprehensive Income (Loss) - Summary of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 67,794	$ 77,262	$ 44,159
Other comprehensive income (loss)	717	(1,262)	(976)
Balance at end of period	52,826	67,794	77,262
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(1,080)	182	1,158
Other comprehensive income (loss) before reclassifications	795	(2,139)
Less: amounts reclassified from accumulated other comprehensive income (loss)	78	(877)
Other comprehensive income (loss)	717	(1,262)	(976)
Balance at end of period	$ (363)	$ (1,080)	$ 182