CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities
Net income	$ 40,774	$ 42,190
Adjustments to reconcile net income to net cash provided by operating activities
Provision for losses on accounts receivable	447	28
Depreciation & amortization	5,111	5,074
Stock-based compensation expense	4,295	4,402
Deferred income taxes	723	(383)
Excess tax benefits from stock-based compensation	0	435
Loss on disposal of property and equipment	44	7
Changes in operating assets and liabilities
(Increase) in trade accounts receivable, net	(1,492)	(1,688)
(Increase) decrease in prepaid expenses & other current assets	3,253	(1,866)
(Increase) in other assets	(1,515)	(31)
Increase (decrease) in accounts payable	(5,907)	10,192
Increase (decrease) in accrued expenses	1,397	(363)
Increase in other current liabilities	660	155
Increase in other long-term liabilities	806	1,564
Net cash provided by operating activities	48,596	59,716
Cash flows from investing activities
Purchases of property and equipment	(3,319)	(3,927)
Proceeds from sale of property and equipment	7	6
Capitalized internal use software development costs	(2,632)	(1,762)
Net cash used in investing activities	(5,944)	(5,683)
Cash flows from financing activities
Cash dividends on common stock	(16,043)	0
Proceeds from employee common stock purchases	1,330	1,114
Tax withholdings related to stock-based compensation awards	(2,651)	(2,105)
Net cash used in financing activities	(17,364)	(991)
Net increase in cash	25,288	53,042
Cash, beginning of period	127,009	98,388
Cash, end of period	152,297	151,430
Non-cash investing activities:
Capital expenditures accrued but not yet paid	88	0
Cash payments:
Income taxes paid	18,490	17,268
Cash dividends on common stock previously restricted for payment of dividend	$ 0	$ 36,456