CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating activities:
Net income	$ 25,943	$ 33,156
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	7,133	8,832
Bad debt expense	1,835	523
Deferred taxes	(4,015)	(2,537)
Share-based compensation expense	6,889	5,075
Excess tax benefits from share-based compensation arrangements	0	(1,208)
Changes in operating assets and liabilities:
Accounts receivable	16,033	12,876
Prepaid expenses and other current assets	(699)	(3,455)
Deposits and other assets	(274)	(2,070)
Accounts payable and accrued expenses	(15,472)	(4,387)
Accrued compensation and employee benefits	(9,685)	(148)
Accrued restructuring costs	0	(33)
Deferred revenue and advance payments	11,072	21,382
Other long-term liabilities	(1,647)	(1,458)
Net cash provided by operating activities	37,113	66,548
Investing activities:
Proceeds from redemption of short-term investments	151,860	152,820
Purchases of property and equipment	(1,467)	(935)
Purchases of short-term investments	(216,602)	(161,818)
Net cash used in investing activities	(66,209)	(9,933)
Financing activities:
Proceeds from sale of class A common stock under exercise of employee stock options	1,677	1,157
Payment of taxes relating to net exercise of employee stock options	0	(3,739)
Excess tax benefits from share-based compensation arrangements	0	1,208
Payments on capital lease obligations and other financing arrangements	(12)	(1,220)
Net cash provided by (used in) financing activities	1,665	(2,594)
Effect of foreign exchange rate changes on cash, cash equivalents, and restricted cash	5,246	1,052
Net (decrease) increase in cash, cash equivalents, and restricted cash	(22,185)	55,073
Cash, cash equivalents and restricted cash, beginning of period	402,712	292,959
Cash, cash equivalents and restricted cash, end of period	$ 380,527	$ 348,032