Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Deficit	Accum. Other Comp. Loss	Total CVG Stockholders’ Equity	Non- Controlling Interest
Beginning Balance (in shares) at Dec. 31, 2013		28,860,143
Beginning Balance at Dec. 31, 2013	$ 59,941	$ 296	$ (6,095)	$ 229,137	$ (137,122)	$ (26,308)	$ 59,908	$ 33
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock (in shares)		378,597
Issuance of restricted stock	0	$ 0					0
Surrender of common stock by employees (in shares)		(90,236)
Surrender of common stock by employees	(527)		(527)				(527)
Share-based compensation expense	2,770			2,770			2,770
Total comprehensive (loss) income	(3,349)				7,630	(10,980)	(3,350)	1
Non-controlling interests	1							1
Ending balance (in shares) at Dec. 31, 2014		29,148,504
Ending balance at Dec. 31, 2014	58,836	$ 296	(6,622)	231,907	(129,492)	(37,288)	58,801	35
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock (in shares)		400,195
Issuance of restricted stock	4	$ 4					4
Surrender of common stock by employees (in shares)		(99,920)
Surrender of common stock by employees	(423)	$ 6	(417)				(423)
Share-based compensation expense	2,853			2,853			2,853
Total comprehensive (loss) income	4,695				7,061	(2,366)	4,695	(35)
Total comprehensive (loss) income, including deconsolidation of noncontrolling interest	$ 4,660
Ending balance (in shares) at Dec. 31, 2015	29,448,779	29,448,779
Ending balance at Dec. 31, 2015	$ 65,930	$ 294	(7,039)	234,760	(122,431)	(39,654)	65,930	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock (in shares)		557,584
Issuance of restricted stock	$ 5	$ 5					5
Surrender of common stock by employees (in shares)	(135,009)	(135,009)
Surrender of common stock by employees	$ (714)		(714)				(714)
Share-based compensation expense	2,607			2,607			2,607
Recognition of excess tax benefits on share-based compensation expense	2,268				2,268		2,268
Total comprehensive (loss) income	$ (2,406)				6,785	(9,191)	(2,406)	0
Ending balance (in shares) at Dec. 31, 2016	29,871,354	29,871,354
Ending balance at Dec. 31, 2016	$ 67,690	$ 299	$ (7,753)	$ 237,367	$ (113,378)	$ (48,845)	$ 67,690	$ 0