Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 32,067	$ 43,652
Accounts receivable, net of allowances of $2,390 and $2,563	232,758	223,630
Prepaid expenses and other current assets	13,754	10,515
Prepaid income taxes	1,957	698
Deferred income taxes	4,334	3,850
Total current assets	284,870	282,345
Property and equipment, net of accumulated depreciation of $80,586 and $75,159	20,579	22,090
Deferred income taxes	5,996	7,061
Goodwill	61,991	62,009
Other intangible assets, net	15,563	16,782
Other non-current assets	9,529	10,418
Total assets	398,528	400,705
Current liabilities:
Short-term borrowings	0	2,751
Cash overdraft	997	0
Accounts payable	34,402	41,157
Accrued compensation and related expenses	51,222	43,571
Other accrued expenses and other current liabilities	11,487	14,970
Income taxes payable	321	1,759
Total current liabilities	98,429	104,208
Deferred compensation	7,446	8,398
Deferred income tax	2,970	1,875
Other non-current liabilities	4,400	6,444
Total liabilities	113,245	120,925
Commitments and contingencies
Equity:
Preferred stock, $0.10 par value - authorized 1,000 shares; none issued	0	0
Common stock	2,195	2,182
Additional paid-in-capital	69,496	67,863
Retained earnings	265,315	259,912
Accumulated other comprehensive (loss) income	(191)	1,501
Common stock in treasury, at cost - 2,463 shares	(52,487)	(52,487)
Total CDI shareholders' equity	284,328	278,971
Noncontrolling interest	955	809
Total equity	285,283	279,780
Total liabilities and equity	398,528	400,705
Common Class B [Member]
Equity:
Common stock	$ 0	$ 0