Segment Reporting - Summary of Revenues, Gross Profit and Operating Income (Loss) by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 339,679	$ 341,872	$ 999,570	$ 1,021,520
Gross profit	72,673	73,442	205,230	220,622
Operating income (loss)	13,009	(75,271)	30,649	(39,564)
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	262,298	250,815	779,206	787,046
Gross profit	57,043	56,295	165,203	179,029
Operating income (loss)	12,604	(57,799)	32,983	(25,752)
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	35,920	41,939	95,185	98,053
Gross profit	7,265	9,099	17,494	19,703
Operating income (loss)	4,055	1,148	7,170	5,086
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	16,281	17,367	48,135	51,656
Gross profit	2,931	2,989	5,467	9,414
Operating income (loss)	(4,423)	(2,860)	(10,473)	(2,672)
Other foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	25,180	31,751	77,044	84,765
Gross profit	5,434	5,059	17,066	12,476
Operating income (loss)	$ 773	$ (15,760)	$ 969	$ (16,226)