CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	[3]
Cash flows from operating activities
Net loss	$ (29,325)	$ (25,081)	[1],[2]
Adjustments to reconcile net loss to net cash provided by operating activities
Depreciation and amortization	9,865	7,923
Share-based compensation	26,988	19,104
Amortization of deferred costs	4,510	3,179
Amortization of debt discount and issuance costs	720	0
Other	250	697
Changes in operating assets and liabilities:
Accounts receivable	3,691	(2,316)
Prepaid expenses and other current assets	(3,364)	(380)
Deferred costs	(7,043)	(4,102)
Other assets and liabilities	(12,027)	(332)
Accounts payable	1,052	1,958
Accrued liabilities	10,986	2,524
Accrued compensation and related benefits	(971)	(2,596)
Deferred revenue	10,910	6,704
Net cash provided by operating activities	16,242	7,282
Cash flows from investing activities
Purchases of property and equipment	(6,808)	(4,791)
Internal-use software development costs	(2,344)	(1,852)
Purchases of marketable securities	(78,321)	(40,758)
Proceeds from maturities of marketable securities	55,263	31,654
Proceeds from sales of marketable securities	6,982	8,602
Net cash used in investing activities	(25,228)	(7,145)
Cash flows from financing activities
Proceeds from issuance of convertible senior notes, net of issuance costs paid of $12,937	562,063	0
Purchase of capped call related to convertible senior notes	(63,940)	0
Proceeds from exercises of employee stock options	6,193	11,689
Proceeds from employee stock purchase plan	5,096	3,844
Taxes paid related to net share settlement of share-based awards	(734)	(154)
Net cash provided by financing activities	508,678	15,379
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(35)	198
Net increase in cash, cash equivalents and restricted cash	499,657	15,714
Cash, cash equivalents and restricted cash at beginning of period	110,888	95,062
Cash, cash equivalents and restricted cash at end of period	610,545	110,776
Reconciliation of cash, cash equivalents and restricted cash to condensed consolidated balance sheets
Total cash, cash equivalents and restricted cash	110,888	95,062
Supplemental cash flow data
Cash paid for income taxes and interest	918	196
Non-cash investing and financing activities
Balance of property and equipment in accounts payable and accrued expenses	3,504	1,460
Property and equipment acquired through tenant improvement allowances	1,370	0
Share-based compensation capitalized in internal-use software development costs	850	694
Estimated convertible senior notes offering costs incurred but not yet paid	850	0
Vesting of early exercised stock options	$ 0	$ 115

[1] See Note 1 for a summary of adjustments.

[2] See Note 1 for a summary of adjustments.

[3] See Note 1 for a summary of adjustments.