Leases - Summary of Maturities of Operating and Finance Lease Liabilities (Parenthetical) (Details) $ in Millions	Oct. 31, 2019 USD ($)
Leases [Abstract]
Non-cancellable sublease proceeds for the year ending January 31, 2020	$ 1.4
Non-cancellable sublease proceeds for the year ending January 31, 2021	9.5
Non-cancellable sublease proceeds for the year ending January 31, 2022	7.1
Non-cancellable sublease proceeds for the year ending January 31, 2023	$ 6.1