Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities
Net income	$ 62,876	$ 46,584	$ 39,369
Adjustments to reconcile net income to net cash provided by operating activities:
Bad debt expense	1,480	1,089	268
Deferred income taxes	(7,390)	6,535	2,106
Non-cash equity compensation	10,291	9,082	10,850
Depreciation and amortization	28,579	29,119	33,406
Deferred rent	(177)	(43)	1,002
Proceeds from hedge sale		3,600
Facilities consolidation reserve	1,479
Amortization of debt issuance costs	673	532	532
Other adjustments, net	275	(1,169)	1,254
Changes in operating assets and liabilities, net of the effect of acquisitions:
Contract receivables	(7,234)	(29,020)	(2,713)
Prepaid expenses and other assets	(1,844)	(2,792)	(170)
Accounts payable	3,631	8,941	(2,374)
Accrued salaries and benefits	5,597	1,140	(13,208)
Accrued expenses and other current liabilities	13,257	10,252	(4,522)
Deferred revenue	8,341	(707)	2,367
Income tax receivable and payable	(5,697)	(2,447)	8,356
Other liabilities	3,054	(639)	(320)
Net Cash Provided by Operating Activities	117,191	80,057	76,203
Cash Flows from Investing Activities
Capital expenditures for property and equipment and capitalized software	(14,513)	(13,791)	(12,682)
Payments for business acquisitions, net of cash received	(91)	(100)	(1,818)
Net Cash Used in Investing Activities	(14,604)	(13,891)	(14,500)
Cash Flows from Financing Activities
Advances from working capital facilities	590,225	478,584	381,745
Payments on working capital facilities	(643,363)	(530,728)	(420,265)
Payments on capital expenditure obligations	(4,808)	(4,041)	(3,289)
Debt issue costs	(1,612)		(17)
Proceeds from exercise of options	4,722	3,034	932
Tax benefits of stock option exercises and award vesting			1,307
Net payments for stockholder issuances and buybacks	(32,464)	(13,823)	(24,861)
Net Cash Used in Financing Activities	(87,300)	(66,974)	(64,448)
Effect of Exchange Rate Changes on Cash, Cash Equivalents, and Restricted Cash	1,094	(416)	(1,746)
Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash	16,381	(1,224)	(4,491)
Cash, Cash Equivalents, and Restricted Cash, Beginning of Period	7,885	9,109	13,600
Cash, Cash Equivalents, and Restricted Cash, End of Period	24,266	7,885	9,109
Supplemental disclosure of cash flow information:
Interest	7,922	8,937	9,845
Income taxes	$ 21,659	$ 21,094	16,315
Non-cash investing and financing transactions:
Capital expenditure obligations			$ 12,870