Leases - Supplemental Disclosure (Details) - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Leases [Abstract]
Cash paid for operating lease liabilities	$ 39,613	$ 29,208
Operating lease liabilities arising from obtaining right-of-use assets	$ 148,007	$ 99,167