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
Beginning Balance (in shares) at Dec. 31, 2015		29,448,779
Beginning balance at Dec. 31, 2015		$ 294	$ (7,039)	$ 234,760	$ (122,431)	$ (39,654)	$ 65,930
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock (in shares)		557,584
Issuance of restricted stock		$ 5					5
Surrender of common stock by employees (in shares)		(135,009)
Surrender of common stock by employees			(714)				(714)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ (2,406)				6,785	(9,191)	(2,406)
Share-based compensation expense				2,607			2,607
Recognition of excess tax benefits on share-based compensation expense					2,268		2,268
Ending balance (in shares) at Dec. 31, 2016		29,871,354
Ending balance at Dec. 31, 2016		$ 299	(7,753)	237,367	(113,378)	(48,845)	67,690
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock (in shares)		509,306
Issuance of restricted stock		$ 5					5
Surrender of common stock by employees (in shares)		(161,382)
Surrender of common stock by employees			(1,361)				(1,361)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 5,905				(1,705)	7,610	5,905
Share-based compensation expense				2,503			2,503
Ending balance (in shares) at Dec. 31, 2017	30,219,278	30,219,278
Ending balance at Dec. 31, 2017	$ 74,742	$ 304	(9,114)	239,870	(115,083)	(41,235)	74,742
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock (in shares)		452,021
Issuance of restricted stock		$ 14					14
Surrender of common stock by employees (in shares)		(158,456)
Surrender of common stock by employees			(1,131)				(1,131)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 38,276				44,512	(6,236)	38,276
Share-based compensation expense				3,137			3,137
Ending balance (in shares) at Dec. 31, 2018	30,512,843	30,512,843
Ending balance at Dec. 31, 2018	$ 115,038	$ 318	$ (10,245)	$ 243,007	$ (70,571)	$ (47,471)	$ 115,038