Commitment and Contingencies (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2021	Jul. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Sublease income	$ 3,200,000	$ 3,200,000	$ 6,400,000	$ 6,400,000
Cost of matching contributions	0	$ 0	0	$ 0
Letters of credit outstanding	$ 16,800,000		$ 16,800,000