CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Cash flows from operating activities
Net loss	$ (768,432)	$ (313,940)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization	67,269	46,079
Amortization of deferred commissions	99,217	75,078
Amortization of investment premiums (accretion of discounts), net	(890)	(7,969)
Amortization of debt discount and issuance costs	71,655	59,477
Gain on extinguishment of convertible senior notes	(6,952)	0
Repurchase of convertible senior notes attributable to the accreted interest related to debt discount	(22,149)	0
Non-cash operating lease costs	15,783	7,511
Stock-based compensation	452,481	378,928
Disposal of property and equipment	981	0
Deferred income taxes	(2,009)	(398)
Changes in operating assets and liabilities, net of acquisitions
Accounts receivable, net	190,893	(165,735)
Prepaid expenses and other assets	(14,456)	(181,201)
Deferred commissions	(99,771)	(84,461)
Accounts payable	(5,179)	(1,129)
Accrued compensation	310	(12,821)
Accrued expenses and other liabilities	(13,497)	2,619
Deferred revenue	(132,350)	(30,843)
Net cash used in operating activities	(167,096)	(228,805)
Cash flows from investing activities
Purchases of investments	(87,135)	(815,685)
Maturities of investments	743,320	805,971
Acquisitions, net of cash acquired	(11,758)	(576,296)
Purchases of property and equipment	(28,307)	(53,524)
Capitalized software development costs	(10,703)	0
Other investment activities	(3,461)	(3,750)
Net cash provided by (used in) investing activities	601,956	(643,284)
Cash flows from financing activities
Proceeds from the exercise of stock options	3,084	624
Proceeds from employee stock purchase plan	44,214	34,482
Proceeds from the issuance of convertible senior notes, net of issuance costs	1,246,544	0
Purchase of capped calls	(137,379)	0
Partial repurchase of convertible senior notes	(668,929)	0
Taxes paid related to net share settlement of equity awards	(49,235)	(164,160)
Net cash provided by (used in) financing activities	438,299	(129,054)
Effect of exchange rate changes on cash and cash equivalents	451	(1,552)
Net increase (decrease) in cash and cash equivalents	873,610	(1,002,695)
Cash and cash equivalents at beginning of period	778,653	1,876,165
Cash and cash equivalents at end of period	1,652,263	873,470
Supplemental disclosures
Cash paid for income taxes	8,406	16,629
Cash paid for interest	22,861	15,761
Non-cash investing activities
Increase in accrued purchases of property and equipment	10,455	11,853
Equity consideration for acquisitions	0	363,139
Vesting of early exercised options	$ 164	$ 0