Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flow from operating activities:
Net income	$ 73,973	$ 30,764
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	170,910	100,840
Stock-based compensation expense	40,402	31,435
Income tax benefit related to exercise of stock options	(44,975)	(11,141)
Amortization and write-offs of loan origination costs	7,994	5,473
Loss on extinguishment of debt		3,954
Loss on sale or disposition of property and equipment	159	339
Deferred income taxes	(39,712)	(27,030)
Provision for doubtful accounts	2,684	601
Changes in operating assets and liabilities, excluding effects from acquisitions:
Accounts receivable	(14,603)	(5,234)
Prepaid expenses and other assets	(2,595)	(5,109)
Accounts payable	2,610	(1,755)
Accrued expenses	(18,429)	(28,437)
Income taxes prepaid and payable	44,840	(1,125)
Deferred revenue	13,758	26,992
Net cash provided by operating activities	237,016	120,567
Cash flow from investing activities:
Additions to property and equipment	(18,870)	(9,462)
Proceeds from sale of property and equipment	69	56
Cash paid for business acquisitions, net of cash acquired	(309,432)	(2,614,785)
Additions to capitalized software	(6,137)	(3,370)
Purchase of long-term investment	(1,000)
Net changes in restricted cash	700
Net cash used in investing activities	(334,670)	(2,627,561)
Cash flow from financing activities:
Cash received from debt borrowings, net of original issue discount		3,068,075
Repayments of debt	(268,550)	(823,448)
Proceeds from exercise of stock options	34,767	10,618
Withholding taxes related to equity award net share settlement	(7,051)
Income tax benefit related to exercise of stock options	44,975	11,141
Proceeds from common stock issuance, net		717,802
Purchase of common stock for treasury	(13)
Payment of fees related to refinancing activities	(503)	(45,781)
Dividends paid on common stock	(37,452)	(33,216)
Net cash (used in) provided by financing activities	(233,827)	2,905,191
Effect of exchange rate changes on cash and cash equivalents	(878)	(3,964)
Net (decrease) increase in cash and cash equivalents	(332,359)	394,233
Cash and cash equivalents, beginning of period	434,159	109,577
Cash and cash equivalents, end of period	$ 101,800	$ 503,810