Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Operating activities
Net loss	$ (99,886)	$ (80,463)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	19,776	10,812
Amortization of deferred commissions	19,167	13,616
Stock-based compensation expense	81,453	80,296
Gain on property and equipment, and lease termination	0	(13,783)
Lease exit costs	7,828	0
Amortization of debt discount and issuance costs	2,762	0
Other	2,864	(1,463)
Changes in assets and liabilities:
Trade and other receivables	52,783	36,627
Deferred commissions	(32,811)	(24,108)
Prepaid expenses and other current assets	(220)	(5,849)
Other noncurrent assets	(3,421)	92
Accounts payable	6,676	2,655
Deferred revenue	(71,387)	(49,921)
Accrued expenses and other current liabilities	(3,088)	10,410
Other noncurrent liabilities	6,308	17
Net cash used in operating activities	(11,196)	(21,062)
Investing activities
Purchases of property, equipment and other	(14,829)	(14,250)
Purchase of marketable securities	(294,220)	(76,122)
Maturities of marketable securities	250,733	53,604
Proceeds from sale of marketable securities	1,100	511
Acquisitions, net of cash acquired	(223,647)	(75,238)
Other	0	(1,500)
Net cash used in investing activities	(280,863)	(112,995)
Financing activities
Proceeds from issuance of convertible senior notes, net of issuance costs	558,998	0
Purchase of capped calls related to convertible senior notes	(61,870)	0
Proceeds from initial public offering net of issuance costs, underwriters discounts and commissions, and concurrent private placement	0	319,972
Proceeds from Series F convertible preferred stock, net of issuance costs	0	69,848
Proceeds from revolving line of credit	43,000	0
Repayment of revolving line of credit	(43,000)	0
Proceeds from exercise of stock options	57,724	16,451
Payments for employee taxes withheld upon vesting of restricted stock units	0	(15,592)
Proceeds from share purchase plan	17,828	0
Principal payments on capital leases	(3,405)	(2,505)
Repayment of debt assumed in acquisitions and other	(6,445)	(2,297)
Net cash provided by financing activities	562,830	385,877
Effect of exchange rate changes on cash and cash equivalents	51	(45)
Net increase in cash and cash equivalents	270,822	251,775
Cash and cash equivalents at beginning of period	226,866	44,876
Cash and cash equivalents at end of period	497,688	296,651
Supplemental disclosures of cash flow information
Cash paid for interest	971	469
Cash paid for income taxes	667	1,208
Noncash investing and financing activities
Other receivables related to stock option exercises	94	0
Vesting of early exercised stock options	0	453
Accrued unpaid issuance costs related to convertible senior notes	760	0
Accrued unpaid issuance costs related to initial public offering	0	400
Accrued unpaid purchase price related to acquisitions	0	2,729
Accrued unpaid capital expenditures	$ 7,779	$ 6,573