Consolidated Statements of Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements of Income
Revenues before reimbursements	$ 743,383	$ 695,714	$ 623,461
Reimbursements	101,258	88,970	80,199
Total revenues	844,641	784,684	703,660
Cost of services before reimbursable expenses	494,972	467,045	418,523
Reimbursable expenses	101,258	88,970	80,199
Total costs of services	596,230	556,015	498,722
General and administrative expenses	141,155	130,415	121,685
Depreciation expense	14,986	13,303	14,457
Amortization expense	6,767	8,658	12,368
Office consolidation	580		(900)
Intangible assets impairment			7,307
Contingent acquisition liability adjustment	1,065
Operating income	83,858	76,293	50,021
Interest expense	5,453	7,292	10,704
Interest income	(872)	(1,447)	(1,309)
Other expense (income), net	(78)	(279)	(567)
Income before income tax expense	79,355	70,727	41,193
Income tax expense	33,186	29,597	17,136
Net income	46,169	41,130	24,057
Basic net income per share	$ 0.91	$ 0.81	$ 0.49
Shares used in computing income per basic share	50,894	50,820	49,405
Diluted net income per share	$ 0.90	$ 0.80	$ 0.48
Shares used in computing income per diluted share	51,572	51,371	50,447
Foreign currency translation adjustment	4,088	(750)	(1,089)
Unrealized income on interest rate derivative, net of income tax costs or benefits	(31)	604	1,478
Other Comprehensive income	4,057	(146)	389
Other Comprehensive income	4,057	(146)	389
Comprehensive income	$ 50,226	$ 40,984	$ 24,446