Income Taxes - Components Of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Jan. 31, 2022	Jan. 31, 2021
Income Tax Disclosure [Abstract]
Stock-based compensation	$ 55.8	$ 39.0
Research and development tax credit carryforwards	249.7	220.4
Foreign tax credit carryforwards	55.9	69.9
Accrued compensation and benefits	5.7	3.4
Other accruals not currently deductible for tax	23.0	14.1
Purchased technology and capitalized software	88.4	48.2
Fixed assets	24.5	8.1
Lease liability	105.7	114.2
Tax loss carryforwards	53.0	65.5
Deferred revenue	389.6	501.5
Other	23.3	40.2
Total deferred tax assets	1,074.6	1,124.5
Less: valuation allowance	(188.3)	(186.5)
Net deferred tax assets	886.3	938.0
Indefinite lived intangibles	(95.4)	(83.1)
Right-of-use assets	(73.7)	(101.6)
Unremitted earnings of foreign subsidiaries	(5.5)	(1.6)
Total deferred tax liabilities	(174.6)	(186.3)
Net deferred tax assets (liabilities)	$ 711.7	$ 751.7