Business Segments - Schedule of Business Segments Adjusted EBITDA (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Dec. 14, 2015	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting [Abstract]
Adjusted EBITDA		$ 13,640	$ 8,186	$ 20,214	$ 15,535
Depreciation and amortization		(3,233)	(3,514)	(5,849)	(7,173)
Stock-based compensation expense		(1,402)	(1,406)	(2,141)	(2,823)
Stock appreciation rights market-to-market		(46)	0	(46)	0
Restructuring charges	$ (6,700)	(3,698)	0	(7,632)	0
Control remediation-related fees		(175)	(537)	(540)	(537)
Executive search fees		0	(234)	(80)	(234)
Professional fees related to ASC 606 implementation		0	(60)		(1,092)
Sales and use tax audit		(1,235)	0	(1,235)	0
Other professional fees		(376)	(80)	(376)	(80)
Income from operations		3,475	2,355	2,315	3,596
Interest income		104	54	202	115
Interest expense		(2,486)	(1,517)	(5,232)	(3,085)
Other, net		279	(588)	(460)	(1,433)
Income (Loss) before income taxes		1,372	304	(3,175)	(807)
Nonoperating Income (Expense)		$ (2,103)	$ (2,051)	$ (5,490)	$ (4,403)