Segment and Geographic Information - Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 333,998	$ 339,679	$ 335,030	$ 324,861	$ 337,499	$ 341,872	$ 354,473	$ 325,175	$ 1,333,568	$ 1,359,019	$ 1,221,920
Gross profit	61,696	72,673	71,053	61,504	64,190	73,442	79,768	67,412	266,926	284,812	253,927
Operating income (loss)	(1,002)	$ 13,009	$ 14,459	$ 3,181	(3,956)	$ (75,271)	$ 21,495	$ 14,212	29,647	(43,520)	50,791
Long-lived assets	128,660				125,309				128,660	125,309	165,967
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									966,291	1,028,313	924,580
Gross profit									178,024	226,026	194,079
Operating income (loss)									174	(33,583)	28,013
Long-lived assets	105,978				93,472				105,978	93,472	140,099
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									133,612	139,734	129,291
Gross profit									22,823	31,173	28,047
Operating income (loss)									9,482	12,220	16,156
Long-lived assets	7,725				8,816				7,725	8,816	9,464
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									66,794	71,839	60,238
Gross profit									8,379	11,997	11,605
Operating income (loss)									(10,599)	(3,771)	1,089
Long-lived assets	8,295				13,435				8,295	13,435	7,575
Other foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									166,871	119,133	107,811
Gross profit									57,700	15,616	20,196
Operating income (loss)									30,590	(18,386)	5,533
Long-lived assets	$ 6,662				$ 9,586				$ 6,662	$ 9,586	$ 8,829