Pension and Postretirement Plans (Net Benefit Expense (Income)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 28, 2017	Oct. 29, 2016	Oct. 28, 2017	Oct. 29, 2016
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 4	$ 12	$ 12
Interest cost	6	6	19	19
Expected return on plan assets	(9)	(9)	(28)	(27)
Amortization of net loss (gain)	3	4	10	11
Net benefit expense (income)	$ 4	5	13	15
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost
Interest cost		1		1
Expected return on plan assets
Amortization of net loss (gain)		(1)	(1)	(2)
Net benefit expense (income)			$ (1)	$ (1)