CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016
Cash Flows from Operating Activities:
Net income		$ 90,344	$ 73,173
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		43,493	46,171
Stock-based compensation		17,943	19,803
Provision for doubtful accounts and billing adjustments		9,216	8,678
fairvalueadjustmentforcontingentconsideration		0	613
Workers’ compensation provision		2,383	1,939
Other		5,967	4,065
Changes in operating assets and liabilities:
Accounts receivable		(51,936)	(47,385)
Prepaid expenses and income taxes		(958)	6,840
Accounts payable		(135)	(3,525)
Accrued payroll and contract professional pay		14,291	25,352
Income taxes payable		13,426	15,070
Workers’ compensation loss reserves		(1,952)	(1,913)
Other Payments to Acquire Businesses		0	4,780
Other		(3,895)	(1,194)
Net cash provided by operating activities(1)	[1]	138,187	142,907
Cash Flows from Investing Activities:
Cash paid for property and equipment		(18,038)	(20,551)
Cash received from sale of discontinued operations, net		0	6,000
Payments to Acquire Businesses, Net of Cash Acquired		25,828	0
Other		0	(787)
Net cash used in investing activities		(43,866)	(15,338)
Cash Flows from Financing Activities:
Principal payments of long-term debt		(69,500)	(106,000)
Proceeds from long-term debt		37,000	7,000
Payments of Debt Issuance Costs		3,273	889
Proceeds from option exercises and employee stock purchase plan		7,690	9,458
Payment of employment taxes related to release of restricted stock awards		(7,785)	(5,968)
Repurchase of common stock		(58,949)	(21,470)
Payments of Merger Related Costs, Financing Activities		0	16,814
Net cash used in financing activities(1)	[1]	(94,817)	(134,683)
Effect of exchange rate changes on cash and cash equivalents		1,429	217
Net Increase (Decrease) in Cash and Cash Equivalents		933	(6,897)
Cash and Cash Equivalents at Beginning of Year		27,044	23,869
Cash and Cash Equivalents at End of Period		27,977	16,972
Supplemental Disclosure of Cash Flow Information:
Income taxes		37,716	23,974
Interest		18,980	20,798
Supplemental Disclosure of Non-Cash Transactions:
Unpaid portion of additions to property and equipment		2,063	1,415
Unsettled repurchases of common stock		$ 1,074	1,100
Excess Tax Benefit from Share-based Compensation, Operating Activities	[1]		$ 2,600

[1] Effective January 1, 2017, the Company adopted ASU No. 2016-09, Compensation - Stock Compensation (Topic 718). The Company elected to present retrospectively its gross excess tax benefits as cash flows from operating activities in the condensed consolidated statements of cash flows for all periods presented, which increased cash flows from operating activities and decreased cash flows from financing activities by $2.6 million for the nine months ended September 30, 2016.