Stock-Based Compensation - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 28, 2018	Oct. 29, 2017	Oct. 28, 2018	Oct. 29, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation expense related to equity awards not expected to vest	$ 73	$ 105	$ 89	$ 144