New Lease Accounting Standard - Schedule of future minimum payments (Details) - USD ($) $ in Millions	Oct. 27, 2019	Jan. 28, 2019	Jan. 27, 2019
Leases [Abstract]
2020 (excluding first nine months of fiscal year 2020)	$ 28
2021	112
2022	104
2023	83
2024	60
2025 and thereafter	282
Total	669
Less imputed interest	111
Present value of net future minimum lease payments	558	$ 500
Less short-term operating lease liabilities	89		$ 0
Long-term operating lease liabilities	$ 469		$ 0