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	$ 85,436	$ 67,560	$ 63,868
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation	21,656	20,506	18,751
Amortization	75,775	66,177	51,216
Amortization of deferred debt issuance costs	6,244	5,877	5,388
Deferred income taxes	19,328	8,437	9,573
Stock-based compensation expense	18,380	11,045	13,572
Excess tax benefit of stock compensation	(4,923)	(11,807)	(6,960)
Gain on available for sale securities	(24,465)
Other	2,725	1,852	(593)
Changes in operating assets and liabilities, net of impact of acquisitions:
Receivables	(11,355)	(30,643)	22,496
Accounts payable	8,557	(3,422)	(13,548)
Accrued employee compensation	(1,998)	(6,360)	(24,501)
Current income taxes	(8,244)	10,968	9,360
Deferred revenue	(4,513)	15,738	(23,613)
Other current and noncurrent assets and liabilities	468	(6,902)	13,409
Net cash flows from operating activities	183,071	149,026	138,418
Cash flows from investing activities:
Purchases of property and equipment	(27,283)	(17,627)	(21,104)
Purchases of software and distribution rights	(21,622)	(17,273)	(11,497)
Proceeds from available-for-sale securities	35,311
Acquisition of businesses, net of cash acquired	(179,367)	(204,290)	(378,113)
Other	(7,000)	(1,500)
Net cash flows from investing activities	(199,961)	(240,690)	(410,714)
Cash flows from financing activities:
Proceeds from issuance of common stock	3,104	2,780	2,186
Proceeds from exercises of stock options	12,175	16,461	19,561
Excess tax benefit of stock compensation	4,923	11,807	6,960
Repurchases of common stock		(70,000)	(80,912)
Repurchase of restricted stock and performance shares for tax withholdings	(4,649)	(5,120)	(6,222)
Proceeds from revolving credit facility	298,000	169,500	40,000
Proceeds from term portion of credit agreement		150,000	300,000
Proceeds from issuance of senior notes			300,000
Repayments of revolving credit facility	(164,000)	(125,500)	(228,000)
Repayment of term portion of credit agreement	(87,352)	(57,449)	(30,867)
Payments on other debt and capital leases	(12,638)	(8,344)	(14,024)
Payment for debt issuance costs		(4,662)	(17,042)
Distribution to noncontrolling interest		(1,391)
Net cash flows from financing activities	49,563	78,082	291,640
Effect of exchange rate fluctuations on cash	(7,735)	(4,176)	(614)
Net increase (decrease) in cash and cash equivalents	24,938	(17,758)	18,730
Cash and cash equivalents, beginning of period	77,301	95,059	76,329
Cash and cash equivalents, end of period	102,239	77,301	95,059
Supplemental cash flow information
Income taxes paid, net	24,036	23,082	20,191
Interest paid	$ 35,183	$ 33,269	$ 14,598