Interim Financial Information - (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 226,191	$ 224,200	$ 225,864	$ 196,202	$ 224,043	$ 211,906	$ 196,300	$ 218,440	$ 872,457	$ 850,689	$ 927,964
Gross profit	63,340	60,310	60,818	54,638	65,574	60,040	56,650	62,988	239,106	245,252	262,067
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	3,553	(20,919)	(9,578)	(12,174)	(6,176)	(5,226)	(15,869)	2,832	(39,118)	(24,439)	(44,025)
Net loss	$ 1,938	$ (22,759)	$ (10,698)	$ (14,044)	$ (5,117)	$ (7,276)	$ (16,619)	$ 732	$ (45,563)	$ (28,280)	$ (53,327)
Net earnings (loss) per share - basic	$ 0.06	$ (0.65)	$ (0.31)	$ (0.41)	$ (0.15)	$ (0.21)	$ (0.48)	$ 0.02	$ (1.31)	$ (0.83)	$ (1.59)
Net Earnings (loss) per Share - Assuming Dilution (in dollars per share)	$ 0.05	$ (0.65)	$ (0.31)	$ (0.41)	$ (0.15)	$ (0.21)	$ (0.48)	$ 0.02	$ (1.31)	$ (0.83)	$ (1.59)