Consolidated Statements Of Shareholders' Equity (USD $) In Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-In-Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total CDI Shareholders' Equity [Member]	Noncontrolling Interest [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2010	$ 258,927	$ 2,153	$ (52,487)	$ 60,338	$ 248,467	$ 111	$ 258,582	$ 345
Common Stock, Shares, Outstanding at Dec. 31, 2010		21,531
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	15,618				15,490		15,490	128
Translation adjustments	(1,184)					(1,136)	(1,136)	(48)
Stock-based compensation	2,291			2,291			2,291
Adjustments to Additional Paid in Capital Reclassification of Equity Awards from Liabilities Net	1,139			1,139			1,139
Vesting of equity awards, Value	0	15		(15)			0
Vesting of equity awards, shares		146
Common shares withheld for taxes, value	(540)	(4)		(536)			(540)
Common shares withheld for taxes, shares		(36)
Dividends, Common Stock, Cash	(7,463)				(7,463)		(7,463)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Sep. 30, 2011	268,788	2,164	(52,487)	63,217	256,494	(1,025)	268,363	425
Common Stock, Shares, Outstanding at Sep. 30, 2011		21,641
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2011	267,031	2,164	(52,487)	63,860	253,344	(306)	266,575	456
Common Stock, Shares, Outstanding at Dec. 31, 2011		21,642
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	14,391				14,124		14,124	267
Translation adjustments	2,897					2,852	2,852	45
Stock-based compensation	2,549			2,549			2,549
Adjustments to Additional Paid in Capital Reclassification of Equity Awards from Liabilities Net	1,205			1,205			1,205
Vesting of equity awards, Value	0	20		(20)			0
Vesting of equity awards, shares		203
Common shares withheld for taxes, value	(733)	(4)		(729)			(733)
Common shares withheld for taxes, shares		(45)
Dividends, Common Stock, Cash	(7,517)				(7,517)		(7,517)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Sep. 30, 2012	$ 279,823	$ 2,180	$ (52,487)	$ 66,865	$ 259,951	$ 2,546	$ 279,055	$ 768
Common Stock, Shares, Outstanding at Sep. 30, 2012		21,800