Leases Balance Sheet Information (Details) $ in Millions	Jan. 31, 2020 USD ($)
Leases [Abstract]
Operating lease right of use assets	$ 107
Finance Lease, Right-of-Use Asset	2
Lease, Right-of-Use Asset	109
Operating Lease, Liability, Current	28
Operating Lease, Liability, Noncurrent	81
Finance Lease, Liability, Noncurrent	2
Lease, Liability	$ 111
Finance Lease, Weighted Average Remaining Lease Term	9 years 6 months
Operating Lease, Weighted Average Remaining Lease Term	5 years
Finance Lease, Weighted Average Discount Rate, Percent	5.90%
Operating Lease, Weighted Average Discount Rate, Percent	4.10%