Segment Reporting - Reconciliation of Net Income to EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting [Abstract]
Net income	$ 6,451	$ 14,090	$ 16,546	$ 31,251
Provision (benefit) for income taxes	2,873	(2,510)	16,580	4,155
Interest expense, net	3,990	3,428	11,580	9,530
Depreciation and amortization	11,130	10,864	31,776	33,317
EBITDA	$ 24,444	$ 25,872	$ 76,482	$ 78,253