Basic and Diluted Earnings Per Share (EPS) Data Numerator and Denominator Calculation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share, Basic and Diluted [Abstract]
Net income (loss) attributable to CDI	$ (1,454)	$ (17,818)	$ (7,484)	$ (4,817)	$ (17,114)	$ (20,202)	$ (157)	$ 470	$ (31,573)	$ (37,003)	$ 3,082
Basic weighted-average shares (in shares)									19,031,000	19,676,000	19,577,000
Dilutive effect o stock-based awards (in shares)									0	0	213,000
Diluted weighted-average shares (in shares)									19,031,000	19,676,000	19,790,000
Basic (in dollars per share)	$ (0.08)	$ (0.96)	$ (0.39)	$ (0.24)	$ (0.87)	$ (1.03)	$ (0.01)	$ 0.02	$ (1.66)	$ (1.88)	$ 0.16
Diluted (in dollars per share)	$ (0.08)	$ (0.96)	$ (0.39)	$ (0.24)	$ (0.87)	$ (1.03)	$ (0.01)	$ 0.02	$ (1.66)	$ (1.88)	$ 0.16
Shares excluded from computation of EPS (in shares)									787,000	502,000	274,000