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, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share, Basic and Diluted [Abstract]
Net income attributable to CDI	$ (7,891)	$ (7,484)	$ (14,728)	$ (12,301)
Basic weighted-average shares	18,739	19,174	18,709	19,427
Dilutive effect of stock-based awards	0	0	0	0
Diluted weighted-average shares	18,739	19,174	18,709	19,427
Earnings per common share:
Basic (per share)	$ (0.42)	$ (0.39)	$ (0.79)	$ (0.63)
Diluted (per share)	$ (0.42)	$ (0.39)	$ (0.79)	$ (0.63)
Antidilutive securities excluded from computation of EPS	400	600	300	600

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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