Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Operating activities:
Net income	$ 88,078	$ 79,506
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	30,252	19,734
Stock-based compensation expense	26,607	27,392
Excess tax benefits from stock-based compensation	(8,469)	(11,117)
Deferred taxes	(845)	2,298
Amortization and write-off of deferred financing fees	2,158	1,595
Changes in assets and liabilities:
Fees receivable, net	(20,380)	13,582
Deferred commissions	15,321	15,539
Prepaid expenses and other current assets	667	(17,193)
Other assets	(1,537)	11,164
Deferred revenues	106,771	93,454
Accounts payable, accrued, and other liabilities	(85,309)	(86,551)
Cash provided by operating activities	153,314	149,403
Investing activities:
Additions to property, equipment and leasehold improvements	(25,337)	(23,614)
Acquisitions - cash paid (net of cash acquired)	(29,896)	0
Cash used in investing activities	(55,233)	(23,614)
Financing activities:
Proceeds from employee stock purchase plan	4,702	3,824
Proceeds from borrowings	830,000	320,000
Payments for debt issuance costs	(4,975)	0
Payments on borrowings	(820,000)	(10,000)
Purchases of treasury stock	(51,967)	(441,442)
Excess tax benefits from stock-based compensation	8,469	11,117
Cash used in financing activities	(33,771)	(116,501)
Net increase in cash and cash equivalents	64,310	9,288
Effects of exchange rates on cash and cash equivalents	7,767	(17,009)
Cash and cash equivalents, beginning of period	372,976	365,302
Cash and cash equivalents, end of period	$ 445,053	$ 357,581