Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 23,409	$ 43,652
Accounts receivable, net of allowances of $2,282 and $2,563	230,762	223,630
Prepaid expenses and other current assets	12,412	10,515
Prepaid income taxes	2,400	698
Deferred income taxes	4,770	3,850
Total current assets	273,753	282,345
Property and equipment, net of accumulated depreciation of $78,609 and $75,159	20,700	22,090
Deferred income taxes	5,997	7,061
Goodwill	61,206	62,009
Other intangible assets, net	15,969	16,782
Other non-current assets	10,700	10,418
Total assets	388,325	400,705
Current liabilities:
Short-term borrowings	0	2,751
Cash overdraft	894	0
Accounts payable	34,396	41,157
Accrued compensation and related expenses	42,655	43,571
Other accrued expenses and other current liabilities	13,541	14,970
Income taxes payable	295	1,759
Total current liabilities	91,781	104,208
Deferred compensation	8,525	8,398
Deferred income tax	2,787	1,875
Other non-current liabilities	4,606	6,444
Total liabilities	107,699	120,925
Commitments and contingencies
Equity:
Preferred stock, $0.10 par value - authorized 1,000 shares; none issued	0	0
Common stock	2,192	2,182
Additional paid-in-capital	68,863	67,863
Retained earnings	263,317	259,912
Accumulated other comprehensive (loss) income	(2,188)	1,501
Common stock in treasury, at cost - 2,463 shares	(52,487)	(52,487)
Total CDI shareholders' equity	279,697	278,971
Noncontrolling interest	929	809
Total equity	280,626	279,780
Total liabilities and equity	388,325	400,705
Common Class B [Member]
Equity:
Common stock	$ 0	$ 0