Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 43,078	$ 45,479
Accounts receivable, net of allowances of $2,000 and $2,893	233,140	230,613
Prepaid expenses and other current assets	11,334	8,033
Prepaid income taxes	736	2,378
Deferred income taxes	4,737	4,724
Total current assets	293,025	291,227
Property and equipment, net of accumulated depreciation of $88,417 and $82,512	21,322	20,528
Deferred income taxes	4,900	5,260
Goodwill	62,053	62,280
Other intangible assets, net	14,034	15,157
Other non-current assets	10,330	11,355
Total assets	405,664	405,807
Current liabilities:
Short-term borrowings	1,932	2,812
Accounts payable	30,973	38,019
Accrued compensation and related expenses	54,057	46,123
Other accrued expenses and other current liabilities	12,025	16,037
Income taxes payable	1,165	245
Total current liabilities	100,152	103,236
Deferred compensation	8,366	9,393
Deferred income tax	4,515	2,994
Other non-current liabilities	4,526	5,010
Total liabilities	117,559	120,633
Commitments and contingencies
Equity:
Preferred stock, $0.10 par value - authorized 1,000 shares; none issued	0	0
Common stock	2,208	2,196
Additional paid-in-capital	71,490	70,104
Retained earnings	269,446	265,207
Accumulated other comprehensive (loss) income	(3,465)	(712)
Common stock in treasury, at cost - 2,463 shares	(52,487)	(52,487)
Total CDI shareholders' equity	287,192	284,308
Noncontrolling interest	913	866
Total equity	288,105	285,174
Total liabilities and equity	405,664	405,807
Common Class B [Member]
Equity:
Common stock	$ 0	$ 0