Basic and Diluted Earnings Per Share (“EPS”) Data (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share, Basic and Diluted [Abstract]
Net income attributable to CDI	$ (157)	$ 4,427	$ 313	$ 6,464
Basic weighted-average shares	19,675	19,565	19,655	19,536
Dilutive effect of stock-based awards	0	202	191	227
Diluted weighted-average shares	19,675	19,767	19,846	19,763
Earnings per common share:
Basic (per share)	$ (0.01)	$ 0.23	$ 0.02	$ 0.33
Diluted (per share)	$ (0.01)	$ 0.22	$ 0.02	$ 0.33
Antidilutive securities excluded from computation of EPS	381	354	206	249