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	14,124				14,124		14,124
Net income	14,391							267
Translation adjustments	2,897					2,852	2,852	45
Share-based compensation expense	2,549			2,549			2,549
Reclassification of equity awards from liabilities, net	1,205			1,205			1,205
Vesting of equity awards (shares)		203
Vesting of equity awards	0	20		(20)			0
Common shares withheld for taxes (shares)		(45)
Common shares withheld for taxes	(733)	(4)		(729)			(733)
Cash dividends paid	(7,517)				(7,517)		(7,517)
Ending balance at Sep. 30, 2012	279,823	2,180	(52,487)	66,865	259,951	2,546	279,055	768
Ending balance (shares) at Sep. 30, 2012		21,800
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	10,457						10,457
Net income	10,616							159
Translation adjustments	(1,705)					(1,692)	(1,692)	(13)
Share-based compensation expense	2,146			2,146			2,146
Reclassification of equity awards from liabilities, net	345			345			345
Vesting of equity awards (shares)		180
Vesting of equity awards	0	18		(18)			0
Common shares withheld for taxes (shares)		(50)
Common shares withheld for taxes	(795)	(5)		(790)			(795)
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	(50)			(50)			(50)
Cash dividends paid	(5,054)				(5,054)		(5,054)
Ending balance at Sep. 30, 2013	$ 285,283	$ 2,195	$ (52,487)	$ 69,496	$ 265,315	$ (191)	$ 284,328	$ 955
Ending balance (shares) at Sep. 30, 2013		21,952