CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - UNAUDITED - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income	$ 38,630	$ 29,131
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	10,554	8,462
Amortization	24,625	20,957
Amortization of original issue discount	1,390	1,313
Asset impairment	365	1,001
Gain on short-term investments and other	(170)	(108)
Loss on extinguishment of debt		810
Deferred income taxes	4,181	4,944
Stock-based compensation	8,500	10,213
Changes in operating assets and liabilities, net of acquired amounts:
Trade accounts receivable, net	(31,751)	(11,369)
Other current and non-current assets and liabilities	(16,222)	(13,995)
Income taxes payable/receivable	(315)	1,828
Trade accounts payable and accrued liabilities	(17,328)	(27,772)
Deferred revenue	5,970	799
Net cash provided by operating activities	28,429	26,214
Cash flows from investing activities:
Purchases of software, property and equipment	(17,858)	(26,715)
Purchases of short-term investments	(22,542)	(44,345)
Proceeds from sale/maturity of short-term investments	28,753	116,866
Acquisition of and investments in business, net of cash acquired	(4,000)	(68,636)
Net cash used in investing activities	(15,647)	(22,830)
Cash flows from financing activities:
Proceeds from issuance of common stock	1,115	1,134
Payment of cash dividends	(14,808)	(14,375)
Repurchase of common stock	(20,741)	(18,319)
Proceeds from long-term debt		150,000
Payments on long-term debt	(3,750)	(121,875)
Payments of deferred financing costs		(1,490)
Net cash used in financing activities	(38,184)	(4,925)
Effect of exchange rate fluctuations on cash	(98)	(1,031)
Net decrease in cash and cash equivalents	(25,500)	(2,572)
Cash and cash equivalents, beginning of period	139,277	122,243
Cash and cash equivalents, end of period	113,777	119,671
Cash paid during the period for:
Interest	8,110	7,744
Income taxes	$ 10,244	$ 4,778