CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jul. 31, 2020	Jul. 31, 2019
Cash flows from operating activities
Net loss	$ (57,932)	$ (40,462)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	22,920	11,330
Accretion of discounts on marketable securities, net	1,099	668
Amortization of deferred commissions	6,437	4,309
Amortization of debt discount and issuance costs	31,357	10,998
Stock-based compensation	58,040	38,113
Gain on conversion of convertible senior notes	(3,202)
Repayments of convertible senior notes attributable to debt discount (Note 9)	(26,336)
Other	3,300	(95)
Changes in operating assets and liabilities net of effects from acquisitions:
Accounts receivable	19,583	20,450
Prepaid expenses and other current assets	7,053	(7,662)
Other assets	901	(770)
Deferred commissions	(6,051)	(9,939)
Accounts payable	(1,741)	(4,473)
Accrued expenses and other liabilities	1,289	(4,061)
Deferred revenue	(17,920)	1,639
Net cash provided by operating activities	38,797	20,045
Cash flows from investing activities
Purchases of marketable securities	(246,586)	(258,991)
Maturities of marketable securities	284,090	44,796
Sales of marketable securities	25,013	199,314
Acquisitions, net of cash acquired	(87,338)	(210,468)
Purchases of property and equipment	(7,028)	(6,173)
Net cash used in investing activities	(31,849)	(231,522)
Cash flows from financing activities
Proceeds from issuance of convertible senior notes, net of issuance costs	1,355,367	786,567
Purchase of capped calls	(192,786)	(118,738)
Repayments of convertible senior notes	(549,278)
Proceeds from the exercise of common stock options	9,609	10,909
Proceeds from issuance of common stock for employee stock purchase plan	7,391	5,396
Net cash provided by financing activities	630,303	684,134
Effects of foreign currency exchange rates on cash, cash equivalents, and restricted cash	241
Net increase in cash, cash equivalents, and restricted cash	637,492	472,657
Cash, cash equivalents, and restricted cash at beginning of year	268,280	141,319
Cash, cash equivalents, and restricted cash at end of period	905,772	613,976
Reconciliation of cash, cash equivalents, and restricted cash to the condensed consolidated balance sheets
Cash and cash equivalents	905,612	613,906
Restricted cash included in other assets	$ 160	$ 70
Restricted cash, asset, statement of financial position [Extensible List]	us-gaap:OtherAssetsNoncurrent	us-gaap:OtherAssetsNoncurrent
Total cash, cash equivalents, and restricted cash	$ 905,772	$ 613,976
Supplemental disclosure of cash flow data
Cash paid for income taxes	1,677	883
Cash paid for interest	533	543
Supplemental disclosure of non-cash investing and financing activities
Property and equipment included in accounts payable and accrued expenses and other current liabilities	$ 324	$ 348