Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash Flows from Operating Activities
Net income	$ 39,369	$ 40,030	$ 39,330
Adjustments to reconcile net income to net cash provided by operating activities:
Bad debt expense	268	272	112
Deferred income taxes	2,106	4,071	2,434
Non-cash equity compensation	10,850	11,008	8,891
Depreciation and amortization	33,406	23,806	20,715
Deferred rent	1,002	2,685	2,606
Other adjustments, net	1,786	(3,015)	1,972
Changes in operating assets and liabilities, net of the effect of acquisitions:
Contract receivables	(2,713)	(2,464)	233
Prepaid expenses and other assets	(170)	(1,743)	(3,633)
Accounts payable	(2,374)	9,424	390
Accrued salaries and benefits	(13,208)	4,286	3,753
Accrued expenses	(4,522)	683	(1,091)
Deferred revenue	2,367	(2,099)	(2,407)
Income tax receivable and payable	8,356	(6,453)	6,749
Restricted cash	116	387	150
Other liabilities	(320)	(1,718)	609
Net Cash Provided by Operating Activities	76,319	79,160	80,813
Cash Flows from Investing Activities
Capital expenditures for property and equipment and capitalized software	(12,682)	(10,635)	(11,859)
Payments for business acquisitions, net of cash received	(1,818)	(347,871)	(4,763)
Net Cash Used in Investing Activities	(14,500)	(358,506)	(16,622)
Cash Flows from Financing Activities
Advances from working capital facilities	381,745	733,032	139,215
Payments on working capital facilities	(420,265)	(422,980)	(204,215)
Payments on capital expenditure obligations	(3,289)	(2,339)	$ (2,302)
Debt issue costs	(17)	(1,245)
Proceeds from exercise of options	932	1,831	$ 3,103
Tax benefits of stock option exercises and award vesting	1,307	3,543	1,213
Net payments for stockholder issuances and buybacks	(24,861)	(28,323)	(7,447)
Net Cash (Used in) Provided by Financing Activities	(64,448)	283,519	(70,433)
Effect of Exchange Rate Changes on Cash	(1,746)	(1,004)	470
(Decrease) Increase in Cash and Cash Equivalents	(4,375)	3,169	(5,772)
Cash and cash equivalents, beginning of period	12,122	8,953	14,725
Cash and cash equivalents, end of period	7,747	12,122	8,953
Supplemental disclosure of cash flow information:
Interest	9,845	2,728	2,459
Income taxes	16,315	$ 24,335	$ 13,670
Non-cash investing and financing transactions:
Capital expenditure obligations	$ 12,870
Fair value of contingent consideration payable in connection with acquisition			$ 2,842