CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2020	Oct. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss		$ (5,284)	$ (40,896)	$ (38,490)	$ (113,958)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization		19,594	16,038	56,382	42,102
Stock-based compensation expense		37,834	37,758	115,438	106,925
Amortization of deferred commissions		9,286	6,650	26,065	18,360
Others		50	7	53	(115)
Changes in operating assets and liabilities:
Accounts receivable, net		7,377	9,510	93,770	66,737
Deferred commissions		(11,464)	(11,617)	(29,290)	(26,571)
Operating lease right-of-use assets, net		10,296	9,007	30,096	26,445
Prepaid expenses and other assets		2,530	1,550	634	(3,289)
Accounts payable		(3,039)	(7,486)	(11,213)	(4,201)
Accrued expenses and other liabilities		320	919	(1,245)	(8,392)
Operating lease liabilities		(11,940)	(7,360)	(33,420)	(24,950)
Deferred revenue		(10,508)	(5,187)	(69,486)	(49,394)
Net cash provided by operating activities		45,052	8,893	139,294	29,699
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment		(3,337)	(1,055)	(7,451)	(4,221)
Capitalized internal-use software costs		(964)	(2,469)	(6,357)	(6,482)
Proceeds from sales of property and equipment				36	6
Proceeds from the sale of a strategic equity investment				107
Net cash used in investing activities		(4,301)	(3,524)	(13,665)	(10,697)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from borrowings				30,000
Principal payment of debt obligation		(20,000)		(20,000)
Proceeds from exercise of stock options		1,363	764	9,874	3,008
Proceeds from issuances of common stock under employee stock purchase plan		6,689	9,820	18,595	23,425
Employee payroll taxes paid related to net share settlement of restricted stock units		(10,776)	(9,494)	(38,220)	(35,055)
Principal payments of finance lease liabilities		(14,584)	(7,055)	(46,159)	(26,200)
Acquisition related contingent consideration					(936)
Net cash used in financing activities		(37,308)	(5,965)	(45,910)	(35,758)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		(49)	(3)	488	(110)
Net increase (decrease) in cash, cash equivalents, and restricted cash		3,394	(599)	80,207	(16,866)
Cash, cash equivalents, and restricted cash, beginning of period		272,399	201,489	195,586	217,756
Cash, cash equivalents, and restricted cash, end of period		275,793	200,890	275,793	200,890
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for interest, net of amounts capitalized		1,762	1,258	5,841	3,768
Cash paid for income taxes, net of tax refunds		114	967	884	2,718
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Accrued equipment purchases		845	3,835	1,203	4,012
Increase in long-lived assets resulting from capitalizing asset retirement costs				297	2,717
Stock-based compensation expense capitalized in internally developed software costs		555	1,188	2,275	3,626
Accrued capitalized internal-use software costs		125		1,086
Increase in finance lease liabilities	[1]	6,072	40,530	29,148	84,950
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH INFORMATION:
Cash and cash equivalents, beginning of period		271,874	201,489	195,586	217,518
Restricted cash, beginning of period		525			238
Cash, cash equivalents, and restricted cash, beginning of period		272,399	201,489	195,586	217,756
Cash and cash equivalents, end of period		275,400	200,890	275,400	200,890
Restricted cash, end of period		393		393
Cash, cash equivalents, and restricted cash, end of period		$ 275,793	$ 200,890	$ 275,793	$ 200,890

[1] Amounts disclosed for the three and nine months ended October 31, 2019 include the adoption impact of ASC Topic 842 on the opening balance sheet as of February 1, 2019.