CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2022	Jul. 31, 2021
Cash flows from operating activities
Net income	$ 90,601	$ 108,858	$ 190,716	$ 224,425
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	7,228	6,880	14,286	13,508
Reduction of operating lease right-of-use assets	3,020	2,874	5,968	5,701
(Accretion) amortization of discount on short-term investments	(507)	1,743	549	3,285
Stock-based compensation	96,042	62,385	163,176	110,874
Amortization of deferred costs	5,736	6,474	11,729	12,829
Deferred income taxes	(20,881)	6,953	(53,313)	12,195
Loss on foreign currency from mark-to-market derivative	1,768	2	1,186	433
Bad debt (recovery) expense	146	(22)	121	137
Changes in operating assets and liabilities:
Accounts receivable	16,312	(21,409)	317,794	280,323
Unbilled accounts receivable	(15,807)	267	(14,512)	(3,894)
Deferred costs	(3,421)	(3,802)	(6,500)	(8,092)
Prepaid expenses and other current and long-term assets	(3,513)	(3,866)	(11,076)	(1,129)
Accounts payable	5,540	5,031	10,661	(1,763)
Accrued expenses and other current liabilities	(475)	2,216	(2,811)	9,183
Income taxes payable	(45,841)	(3,726)	(2,618)	(17)
Deferred revenue	(39,998)	(49,783)	(47,469)	(57,959)
Operating lease liabilities	(3,081)	(2,913)	(5,112)	(5,661)
Other long-term liabilities	517	903	1,638	3,072
Net cash provided by operating activities	93,386	119,065	574,413	597,450
Cash flows from investing activities
Purchases of short-term investments	(433,073)	(422,680)	(1,005,417)	(679,618)
Maturities and sales of short-term investments	250,531	187,324	446,721	408,969
Acquisitions, net of cash acquired	0	(2,133)	0	(2,133)
Long-term assets	(1,663)	(5,325)	(3,996)	(7,981)
Net cash used in investing activities	(184,205)	(242,814)	(562,692)	(280,763)
Cash flows from financing activities
Changes in lease liabilities - finance leases	0	(98)	0	(384)
Proceeds from exercise of common stock options	9,250	20,851	25,541	37,942
Taxes paid related to net share settlement of equity awards	(17,134)	(15,096)	(32,133)	(15,096)
Net cash (used in) provided by financing activities	(7,884)	5,657	(6,592)	22,462
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(1,049)	(180)	(2,923)	(2,945)
Net change in cash, cash equivalents, and restricted cash	(99,752)	(118,272)	2,206	336,204
Cash, cash equivalents, and restricted cash at beginning of period	1,243,183	1,186,188	1,141,225	731,712
Cash, cash equivalents, and restricted cash at end of period	1,143,431	1,067,916	1,143,431	1,067,916
Cash, cash equivalents, and restricted cash at end of period:
Cash and cash equivalents	1,140,246	1,064,731	1,140,246	1,064,731
Restricted cash included in other long-term assets	3,185	3,185	3,185	3,185
Cash, cash equivalents, and restricted cash at end of period	1,143,431	1,067,916	1,143,431	1,067,916
Supplemental disclosures of other cash flow information:
Cash paid for income taxes, net of refunds	89,583	15,368	107,772	20,501
Excess tax benefits from employee stock plans	2,094	17,609	5,093	35,060
Non-cash investing activities:
Changes in accounts payable and accrued expenses related to property and equipment purchases	$ (3)	$ 104	$ (441)	$ (2,826)