Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 18,416	$ 43,652
Accounts receivable, net of allowances of $2,409 and $2,563	237,065	223,630
Prepaid expenses and other current assets	13,149	10,515
Prepaid income taxes	1,341	698
Deferred income taxes	4,262	3,850
Total current assets	274,233	282,345
Property and equipment, net of accumulated depreciation of $76,765 and $75,159	20,951	22,090
Deferred income taxes	6,936	7,061
Goodwill	61,199	62,009
Other intangible assets, net	16,375	16,782
Other non-current assets	10,934	10,418
Total assets	390,628	400,705
Current liabilities:
Short-term borrowings	0	2,751
Cash overdraft	613	0
Accounts payable	32,373	41,157
Accrued compensation and related expenses	44,769	43,571
Other accrued expenses and other current liabilities	14,010	14,970
Income taxes payable	1,180	1,759
Total current liabilities	92,945	104,208
Deferred compensation	8,604	8,398
Deferred income tax	2,482	1,875
Other non-current liabilities	6,095	6,444
Total liabilities	110,126	120,925
Commitments and contingencies
Equity:
Preferred stock, $0.10 par value - authorized 1,000 shares; none issued	0	0
Common stock	2,188	2,182
Additional paid-in-capital	68,197	67,863
Retained earnings	262,403	259,912
Accumulated other comprehensive (loss) income	(718)	1,501
Common stock in treasury, at cost - 2,463 shares	(52,487)	(52,487)
Total CDI shareholders' equity	279,583	278,971
Noncontrolling interest	919	809
Total equity	280,502	279,780
Total liabilities and equity	390,628	400,705
Common Class B [Member]
Equity:
Common stock	$ 0	$ 0