Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net (loss) income	$ (19,587)	$ 36,433
Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities:
Depreciation and amortization	68,056	16,530
Stock-based compensation expense	30,958	22,576
Deferred taxes	(39,175)	(11,998)
Amortization and write-off of deferred financing fees	1,868	468
Changes in assets and liabilities, net of acquisitions:
Fees receivable, net	56,771	(57,919)
Deferred commissions	(512)	3,002
Prepaid expenses and other current assets	(53,851)	(5,315)
Other assets	14,421	(16,730)
Deferred revenues	76,854	92,373
Accounts payable, accrued, and other liabilities	(133,079)	(109,025)
Cash provided by (used in) operating activities	2,724	(29,605)
Investing activities:
Additions to property, equipment and leasehold improvements	(17,679)	(10,700)
Acquisitions - cash paid (net of cash acquired)	0	(111,165)
Other	1,000	0
Cash used in investing activities	(16,679)	(121,865)
Financing activities:
Proceeds from employee stock purchase plan	4,124	3,022
Proceeds from borrowings	0	955,000
Payments for deferred financing fees	0	(18,773)
Payments on borrowings	(304,813)	0
Purchases of treasury stock	(28,394)	(21,978)
Cash (used in) provided by financing activities	(329,083)	917,271
Net (decrease) increase in cash and cash equivalents and restricted cash	(343,038)	765,801
Effects of exchange rates on cash and cash equivalents and restricted cash	3,610	6,007
Cash and cash equivalents and restricted cash, beginning of period	227,630	1,271,162
Cash and cash equivalents and restricted cash, end of period	$ 567,058	$ 499,354