Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities
Net income (loss)	$ 66,053	$ 58,807	$ (10,594)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	31,392	35,126	32,638
Amortization and impairment of other intangible assets	11,726	15,521	22,954
Goodwill impairment charge			83,752
Acquisition-related contingent consideration	(1,200)	(1,676)	(10,869)
Provision for doubtful accounts	15,564	18,252	13,335
Non-cash share-based compensation	17,951	22,848	35,129
Non-cash interest expense	2,521	2,691	2,699
Loss on early extinguishment of debt	19,589
Other	(760)	(522)	(1,582)
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable, billed and unbilled	(35,648)	(43,072)	(56,290)
Notes receivable	3,106	(18,253)	(7,544)
Prepaid expenses and other assets	(3,557)	10,733	(6,784)
Accounts payable, accrued expenses and other	(4,718)	980	8,505
Income taxes	18,491	15,283	7,963
Accrued compensation	4,780	11,106	82,917
Billings in excess of services provided	(5,370)	7,577	(2,958)
Net cash provided by operating activities	139,920	135,401	193,271
Investing activities
Payments for acquisition of businesses, net of cash received	(575)	(23,467)	(55,498)
Purchases of property and equipment	(31,399)	(39,256)	(42,544)
Other	237	5,128	(5,049)
Net cash used in investing activities	(31,737)	(57,595)	(103,091)
Financing activities
Borrowings under revolving line of credit, net	200,000
Payments of long-term debt	(425,671)	(6,014)	(6,021)
Payments of debt issue costs	(3,843)
Deposits	3,227	13,071
Purchase and retirement of common stock	(26,532)	(4,367)	(66,763)
Net issuance of common stock under equity compensation plans	16,666	4,772	29,392
Other	191	(1,132)	263
Net cash (used in) provided by financing activities	(235,962)	6,330	(43,129)
Effect of exchange rate changes on cash and cash equivalents	(6,141)	(6,289)	1,997
Net increase (decrease) in cash and cash equivalents	(133,920)	77,847	49,048
Cash and cash equivalents, beginning of period	283,680	205,833	156,785
Cash and cash equivalents, end of period	149,760	283,680	205,833
Supplemental cash flow disclosures
Cash paid for interest	46,965	48,169	48,156
Cash paid for income taxes, net of refunds	20,654	27,326	35,074
Non-cash investing and financing activities:
Issuance of common stock to acquire businesses			2,883
Issuance of stock units under incentive compensation plans	$ 2,124	$ 1,674	3,005
Unsettled repurchase and retirement of common stock			$ (4,367)