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	8,775				8,775		8,775
Net income	8,985							210
Translation adjustments	(246)					(236)	(236)	(10)
Share-based compensation expense	1,736			1,736			1,736
Reclassification of equity awards from liabilities, net	1,289			1,289			1,289
Vesting of equity awards (shares)		190
Vesting of equity awards	0	19		(19)			0
Common shares withheld for taxes (shares)		(41)
Common shares withheld for taxes	(658)	(4)		(654)			(658)
Cash dividends paid	(5,004)				(5,004)		(5,004)
Ending balance at Jun. 30, 2012	273,133	2,179	(52,487)	66,212	257,115	(542)	272,477	656
Ending balance (shares) at Jun. 30, 2012		21,791
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	5,929						5,929
Net income	6,050							121
Translation adjustments	(3,690)					(3,689)	(3,689)	(1)
Share-based compensation expense	1,385			1,385			1,385
Reclassification of equity awards from liabilities, net	187			187			187
Vesting of equity awards (shares)		134
Vesting of equity awards	0	13		(13)			0
Common shares withheld for taxes (shares)		(31)
Common shares withheld for taxes	(512)	(3)		(509)			(512)
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	(50)			(50)			(50)
Cash dividends paid	(2,524)				(2,524)		(2,524)
Ending balance at Jun. 30, 2013	$ 280,626	$ 2,192	$ (52,487)	$ 68,863	$ 263,317	$ (2,188)	$ 279,697	$ 929
Ending balance (shares) at Jun. 30, 2013		21,925