CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash Flows From Operating Activities
Net loss	$ (32,746)	$ (17,114)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation and amortization expense	10,563	6,170
Non-cash operating lease costs	4,543	0
Amortization of deferred contract acquisition costs	3,499	2,319
Stock-based compensation expense	12,897	1,057
Net accretion of discounts and amortization of premiums on available-for-sale securities	(456)	(518)
Deferred income taxes	(117)	0
Provision for bad debt	2,209	259
Change in fair value of redeemable convertible preferred stock warrant liability	0	118
Other	(197)	4
Changes in operating assets and liabilities, net of effect of acquisitions:
Accounts receivable, net	(8,120)	(5,616)
Contract assets	284	180
Deferred contract acquisition costs	(6,486)	(4,225)
Prepaid expenses and other current assets	(1,086)	(121)
Other noncurrent assets	(658)	(148)
Accounts payable	1,507	(2,553)
Accrued expenses and other current liabilities	40	1,022
Operating lease liabilities	(4,804)	0
Deferred revenue	6,445	7,400
Other noncurrent liabilities	(1,593)	2,076
Net cash used in operating activities	(14,276)	(9,690)
Cash Flows From Investing Activities
Purchases of property and equipment	(11,405)	(9,036)
Capitalized internal-use software	(4,922)	(3,397)
Cash paid for acquisitions, net of cash acquired	(13,639)	0
Purchases of available-for-sale securities	(110,609)	(14,856)
Sales of available-for-sale securities	0	1,978
Maturities of available-for-sale securities	131,580	40,498
Other investing activities	223	22
Net cash provided by (used in) investing activities	(8,772)	15,209
Cash Flows From Financing Activities
Proceeds from the exercise of stock options	2,675	681
Proceeds from the early exercise of stock options	32	1,638
Repurchases of unvested common stock	(70)	(4)
Payments on note payable	(200)	(90)
Proceeds from build-to-suit lease financing obligation drawdown	0	23
Payment of tax withholding obligation on RSU settlement	(7,115)	0
Net cash provided by (used in) financing activities	(4,678)	2,248
Net increase (decrease) in cash, cash equivalents, and restricted cash	(27,726)	7,767
Cash, cash equivalents, and restricted cash, beginning of period	145,636	31,426
Cash, cash equivalents, and restricted cash, end of period	117,910	39,193
Supplemental Disclosure of Cash Flow Information:
Cash paid for interest	34	214
Cash paid for income taxes	163	299
Cash paid for operating lease liabilities	4,477	0
Supplemental Disclosure of Non-cash Investing and Financing Activities:
Stock-based compensation capitalized for software development	578	71
Accounts payable and accrued expenses related to property and equipment additions	4,522	3,493
Vesting of early exercised stock options	1,223	496
Deferred offering costs, accrued but not paid	0	475
Indemnity holdback consideration associated with business combinations	2,188	0
Issuance of common stock related to an acquisition	1,104	0
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	2,386	0
Derecognition of build-to-suit lease	$ 9,886	$ 0