Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net income	$ 46,169	$ 41,130	$ 24,057
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense	14,986	13,303	14,457
Amortization expense	6,767	8,658	12,368
Share-based compensation expense	10,027	8,792	6,755
Accretion of interest expense	630	836	944
Deferred income taxes	11,123	11,264	3,773
Allowance for doubtful accounts receivable	6,329	6,910	8,211
Contingent acquisition liability adjustment	1,065
Intangible assets impairment			7,307
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	(22,821)	(5,817)	(23,990)
Prepaid expenses and other assets	(2,668)	208	(16,146)
Accounts payable	1,754	5,353	2,742
Accrued liabilities	2,879	491	(110)
Accrued compensation-related costs	(10,794)	22,720	3,003
Income taxes payable	4,385	1,705	2,371
Other liabilities	6,131	(4,186)	(3,974)
Net cash provided by operating activities	75,962	111,367	41,768
Cash flows from investing activities:
Purchases of property and equipment	(20,052)	(10,375)	(11,959)
Acquisitions of businesses, net of cash acquired	(27,479)	(9,246)	(62,370)
Payments of acquisition liabilities	(4,856)	(14,967)	(2,750)
Other investing, net	(2,234)	(225)
Net cash used in investing activities	(54,621)	(34,813)	(77,079)
Cash flows from financing activities:
Issuances of common stock	3,283	1,865	3,457
Repurchased of Common Stock	(18,870)	(2,558)
Payments of contingent acquisition liabilities	(8,580)
Payment upon termination of credit agreement		(250,613)
Proceeds From New Credit Agreement		250,613
Borrowings from banks	349,729	218,078	267,524
Repayments to banks	(347,877)	(284,456)	(233,083)
Payments of term loan		(4,599)	(50,119)
Payments of Debt Issuance Costs		(2,814)
Other, net	(1,071)	(907)	494
Net cash provided by (used in) financing activities	(23,386)	(75,391)	(11,727)
Effect of exchange rate changes on cash and cash equivalents	128	(175)	(125)
Net decrease in cash and cash equivalents	(1,917)	988	(47,163)
Cash and cash equivalents at beginning of the period	2,969	1,981	49,144
Cash and cash equivalents at end of the period	1,052	2,969	1,981
Interest Paid	4,149	5,818	9,388
Income taxes paid, net of refunds	$ 15,935	$ 15,501	$ 5,752