Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2023	Jan. 31, 2022	Jan. 31, 2021
Cash flows from operating activities
Net income	$ 487,706	$ 427,390	$ 379,998
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	29,122	27,448	29,455
Reduction of operating lease right-of-use assets	12,198	11,445	10,347
(Accretion) amortization of discount on short-term investments	(3,624)	6,264	3,134
Stock-based compensation	351,907	234,636	185,001
Amortization of deferred costs	22,096	26,050	20,677
Deferred income taxes	(127,502)	11,079	(1,048)
Loss (gain) on foreign currency from mark-to-market derivative	971	(782)	(365)
Bad debt expense (recovery)	256	272	(307)
Changes in operating assets and liabilities:
Accounts receivable	(72,177)	(67,020)	(174,067)
Unbilled accounts receivable	(18,908)	(16,060)	(14,387)
Deferred costs	(20,815)	(17,084)	(27,164)
Prepaid expenses and other current and long-term assets	(47,399)	(2,910)	(12,424)
Accounts payable	21,429	(2,997)	754
Accrued expenses and other current liabilities	9,276	9,439	13,889
Income taxes payable	(2,815)	5,275	(3,023)
Deferred revenue	140,472	116,144	147,479
Operating lease liabilities	(10,644)	(11,607)	(9,129)
Other long-term liabilities	8,921	7,481	2,426
Net cash provided by operating activities	780,470	764,463	551,246
Cash flows from investing activities
Purchases of short-term investments	(1,996,878)	(1,117,076)	(979,292)
Maturities and sales of short-term investments	1,002,707	792,918	654,341
Acquisitions, net of cash and restricted cash acquired	0	(7,780)	0
Long-term assets	(13,512)	(14,214)	(8,683)
Net cash used in investing activities	(1,007,683)	(346,152)	(333,634)
Cash flows from financing activities
Changes in lease liabilities - finance leases	0	(384)	(1,039)
Proceeds from exercise of common stock options	43,654	51,538	34,857
Taxes paid related to net share settlement of equity awards	(63,030)	(55,294)	0
Net cash (used in) provided by financing activities	(19,376)	(4,140)	33,818
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(4,986)	(4,657)	484
Net change in cash, cash equivalents, and restricted cash	(251,575)	409,514	251,914
Cash, cash equivalents, and restricted cash at beginning of period	1,141,225	731,711	479,797
Cash, cash equivalents, and restricted cash at end of period	889,650	1,141,225	731,711
Cash, cash equivalents, and restricted cash at end of period:
Cash and cash equivalents	886,465	1,138,040	730,504
Restricted cash included in other long-term assets	3,185	3,185	1,207
Cash, cash equivalents, and restricted cash at end of period	889,650	1,141,225	731,711
Supplemental disclosures of other cash flow information:
Cash paid for income taxes, net of refunds	167,952	58,627	18,096
Excess tax benefits from employee stock plans	82,009	56,172	80,661
Non-cash investing activities:
Changes in accounts payable and accrued expenses related to property and equipment purchases	$ (454)	$ (2,489)	$ 3,165