Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating activities:
Net income	$ 127,097	$ 109,872
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	46,004	31,922
Stock-based compensation expense	36,128	36,980
Excess tax benefits from stock-based compensation	0	(11,222)
Deferred taxes	(13,415)	(5,724)
Amortization and write-off of deferred financing fees	2,611	2,392
Changes in assets and liabilities:
Fees receivable, net	26,242	57,045
Deferred commissions	12,376	18,251
Prepaid expenses and other current assets	(43,402)	(42,347)
Other assets	21,597	(12,878)
Deferred revenues	114,197	109,595
Accounts payable, accrued, and other liabilities	(47,172)	(27,579)
Cash provided by operating activities	282,263	266,307
Investing activities:
Additions to property, equipment and leasehold improvements	(36,877)	(36,067)
Acquisitions - cash paid (net of cash acquired)	(29,363)	(169,853)
Acquisitions - increase in restricted cash (escrow)	0	25,625
Acquisitions - increase in restricted cash (escrow)	(13,600)
Cash used in investing activities	(66,240)	(231,545)
Financing activities:
Proceeds from employee stock purchase plan	6,931	5,583
Proceeds from borrowings	747,500	450,000
Payments for debt issuance costs	(4,975)	0
Payments on borrowings	(827,500)	(15,000)
Purchases of treasury stock	(52,889)	(453,000)
Excess tax benefits from stock-based compensation	0	11,222
Cash used in financing activities	(130,933)	(1,195)
Net increase in cash and cash equivalents	85,090	33,567
Effects of exchange rates on cash and cash equivalents	7,668	(27,625)
Cash and cash equivalents, beginning of period	372,976	365,302
Cash and cash equivalents, end of period	$ 465,734	$ 371,244