Consolidated Statements Of Shareholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Treasury Stock	Additional Paid-In-Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total CDI Shareholders' Equity	Non-Controlling Interest
Beginning balance at Dec. 31, 2011	$ 267,031	$ 2,164	$ (52,487)	$ 63,860	$ 253,344	$ (306)	$ 266,575	$ 456
Beginning balance (shares) at Dec. 31, 2011		21,642
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to CDI	3,823				3,823		3,823
Net income	3,914							91
Translation adjustments	1,391					1,346	1,346	45
Share-based compensation expense	1,146			1,146			1,146
Reclassification of equity awards from liabilities, net	698			698			698
Vesting of equity awards (shares)		115
Vesting of equity awards	0	12		(12)			0
Common shares withheld for taxes (shares)		(38)
Common shares withheld for taxes	(599)	(4)		(595)			(599)
Cash dividends paid	(2,500)				(2,500)		(2,500)
Ending balance at Mar. 31, 2012	271,081	2,172	(52,487)	65,097	254,667	1,040	270,489	592
Ending balance (shares) at Mar. 31, 2012		21,719
Beginning balance at Dec. 31, 2012	279,780	2,182	(52,487)	67,863	259,912	1,501	278,971	809
Beginning balance (shares) at Dec. 31, 2012		21,822
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to CDI	2,491				2,491		2,491
Net income	2,553							62
Translation adjustments	(2,171)					(2,219)	(2,219)	48
Share-based compensation expense	770			770			770
Reclassification of equity awards from liabilities, net	96			96			96
Vesting of equity awards (shares)		83
Vesting of equity awards	0	8		(8)			0
Common shares withheld for taxes (shares)		(28)
Common shares withheld for taxes	(476)	(2)		(474)			(476)
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	50			(50)			50
Ending balance at Mar. 31, 2013	$ 280,502	$ 2,188	$ (52,487)	$ 68,197	$ 262,403	$ (718)	$ 279,583	$ 919
Ending balance (shares) at Mar. 31, 2013		21,877