Quarterly Results of Operations (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 207,085	$ 149,490	$ 130,144	$ 126,124	$ 198,981	$ 171,017	$ 135,179	$ 124,533
Gross profit	44,912	30,928	27,586	26,119	41,562	38,120	30,323	27,510	$ 129,545	$ 137,515	$ 135,009
Operating profit	25,517	6,991	2,858	1,500	17,540	12,975	4,065	3,590	36,866	38,170	39,928
Income from continuing operations, net of tax	19,394	3,150	1,572	962	12,661	9,933	1,892	2,659	25,078	27,145	20,130
Loss from discontinued operations, net of tax	(20,608)	(2,753)	(2,516)	(2,723)	2,371	(1,889)	(2,766)	(3,077)	(28,600)	(5,361)	(2,225)
Net income (loss)	$ (1,214)	$ 397	$ (944)	$ (1,761)	$ 15,032	$ 8,044	$ (874)	$ (418)	$ (3,522)	$ 21,784	$ 17,905
Earnings Per Share, Basic and Diluted [Abstract]
Basic and diluted earnings per share, continuing operations (in dollars per share)	$ 1.43	$ 0.23	$ 0.11	$ 0.07	$ 0.93	$ 0.72	$ 138.15	$ 194.33	$ 1.83	$ 1.98	$ 1.47
Basic and diluted earnings per share, discontinued operations (in dollars per share)	(1.52)	(0.20)	(0.18)	(0.20)	0.17	(0.13)	(201.97)	(224.88)	$ (2.09)	$ (0.39)	$ (0.16)
Basic earnings (loss) per share (in dollars per share)	$ (0.09)	$ 0.03	$ (0.07)	$ (0.13)	$ 1.10	$ 0.59	$ (60.00)	$ (30.00)