Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net loss	$ (36,642)	$ (14,675)
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of deferred implementation, solution and other costs	6,056	4,265
Depreciation and amortization	11,796	7,752
Amortization of debt issuance costs	545	346
Amortization of debt discount	5,230	3,089
Amortization of premiums on investments	183	21
Stock-based compensation expenses	19,040	13,099
Deferred income taxes	(347)	(61)
Allowance for sales credits	114	38
Loss on disposal of long-lived assets	(226)	0
Unoccupied lease charges	0	658
Changes in operating assets and liabilities:
Accounts receivable, net	(7,037)	(13,831)
Prepaid expenses and other current assets	(1,543)	(1,718)
Deferred solution and other costs	(10,864)	(5,965)
Deferred implementation costs	(6,537)	(2,761)
Contract assets	(3,178)	(2,212)
Other long-term assets	2,120	(225)
Accounts payable	(189)	(825)
Accrued liabilities	(70)	(3,312)
Deferred revenues	5,746	(4,295)
Deferred rent and other long-term liabilities	(2,876)	(672)
Net cash used in operating activities	(18,679)	(21,284)
Cash flows from investing activities:
Purchases of investments	(24,778)	(74,389)
Maturities of investments	58,974	14,058
Purchases of property and equipment	(10,864)	(11,154)
Business combinations and asset acquisitions, net of cash acquired	0	(150)
Purchases of intangible assets	(288)	0
Net cash provided by (used in) investing activities	23,044	(71,635)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance costs	195,581	0
Proceeds from issuance of convertible notes, net of issuance costs	307,288	223,185
Purchases of capped call transactions	(40,765)	0
Purchase of convertible notes bond hedge	0	(41,699)
Proceeds from issuance of warrants	0	22,379
Proceeds from exercise of stock options to purchase common stock	8,422	7,831
Net cash provided by financing activities	470,526	211,696
Net increase in cash, cash equivalents, and restricted cash	474,891	118,777
Cash, cash equivalents, and restricted cash, beginning of period	110,156	60,276
Cash, cash equivalents, and restricted cash, end of period	585,047	179,053
Supplemental disclosures of cash flow information:
Cash paid for taxes	161	130
Cash paid for interest	863	0
Supplemental disclosure of non-cash investing and financing activities:
Shares acquired to settle the exercise of stock options	$ (467)	$ (96)