CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net income	$ 20,244	$ 20,405
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation & amortization	4,596	4,527
Stock-based compensation expense	3,796	2,414
Deferred income taxes	(2,755)	(1,494)
Loss on disposal of property and equipment	29	128
Changes in operating assets and liabilities:
(Increase) in trade accounts receivable, net	(19,008)	(8,393)
Decrease in prepaid expenses & other current assets	1,862	2,370
(Increase) decrease in other assets	8	(42)
Increase in accounts payable	14,047	6,705
(Decrease) in accrued expenses	(1,993)	(4,416)
Increase (decrease) in other current liabilities	(633)	102
Increase in other long-term liabilities	615	413
Net cash provided by operating activities	20,808	22,719
Cash flows from investing activities:
Purchases of property and equipment	(2,204)	(2,653)
Capitalized internal use software development costs	(539)	(657)
Net cash used in investing activities	(2,743)	(3,310)
Cash flows from financing activities:
Proceeds from employee common stock purchases	1,131	1,107
Tax deductions related to stock-based compensation	232	897
Net cash provided by financing activities	1,363	2,004
Net increase in cash	19,428	21,413
Cash, beginning of period	87,983	74,245
Cash, end of period	107,411	95,658
Non-cash investing activities:
Capital expenditures accrued but not yet paid	130	50
Cash payments:
Income taxes paid	$ 13,073	13,837
Cash dividends on common stock previously restricted for payment of dividend		$ 22,982