Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Revenue	$ 263,363	$ 274,398	$ 532,829	$ 555,025
Cost of services	211,818	218,870	431,133	443,812
Gross profit	51,545	55,528	101,696	111,213
Operating and administrative expenses	46,303	47,664	91,541	95,960
Operating profit	5,242	7,864	10,155	15,253
Other income (expense), net	(62)	(80)	(113)	(118)
Income before income taxes	5,180	7,784	10,042	15,135
Income tax expense	1,683	2,713	3,992	6,150
Net income	3,497	5,071	6,050	8,985
Less: Income attributable to the noncontrolling interest	59	119	121	210
Net income attributable to CDI	$ 3,438	$ 4,952	$ 5,929	$ 8,775
Earnings per common share:
Basic (per share)	$ 0.18	$ 0.26	$ 0.31	$ 0.46
Diluted (per share)	$ 0.17	$ 0.25	$ 0.30	$ 0.45