CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
Operating activities:
Net income	$ 155,600,000	$ 66,500,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion	33,000,000.0	30,000,000.0
Stock-based compensation expense	115,800,000	98,200,000
Deferred income taxes	18,800,000	3,500,000
Other	18,600,000	32,700,000
Changes in operating assets and liabilities, net of business combinations:
Accounts receivable	324,400,000	295,500,000
Prepaid expenses and other assets	(125,600,000)	(47,500,000)
Accounts payable and other liabilities	(182,200,000)	(154,600,000)
Deferred revenue	(27,500,000)	(1,100,000)
Accrued income taxes	5,200,000	4,100,000
Net cash provided by operating activities	336,100,000	327,300,000
Investing activities:
Purchases of marketable securities	0	(11,000,000.0)
Sales and maturities of marketable securities	4,000,000.0	0
Capital expenditures	(20,300,000)	(19,900,000)
Purchases of developed technologies	(900,000)	(3,600,000)
Business combinations, net of cash acquired	(1,031,600,000)	0
Other investing activities	8,400,000	(43,500,000)
Net cash used in investing activities	(1,040,400,000)	(78,000,000.0)
Financing activities:
Proceeds from issuance of common stock, net of issuance costs	64,200,000	56,800,000
Taxes paid related to net share settlement of equity awards	(54,900,000)	(32,500,000)
Repurchases of common stock	(151,400,000)	(202,000,000.0)
Repayment of debt	0	(450,000,000.0)
Other financing activities	0	(2,500,000)
Net cash used in financing activities	(142,100,000)	(630,200,000)
Effect of exchange rate changes on cash and cash equivalents	(2,600,000)	(4,100,000)
Net decrease in cash and cash equivalents	(849,000,000.0)	(385,000,000.0)
Cash and cash equivalents at beginning of period	1,772,200,000	1,774,700,000
Cash and cash equivalents at end of period	923,200,000	1,389,700,000
Non-cash financing activities:
Fair value of common stock issued to settle liability-classified restricted stock units	0	28,700,000
Fair value of common stock issued related to business combination	$ 2,600,000	$ 0