Pension and Postretirement Plans (Net Benefit Expense (Income)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 29, 2016	Oct. 31, 2015	Oct. 29, 2016	Oct. 31, 2015
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4	$ 5	$ 12	$ 13
Interest cost	6	6	19	18
Expected return on plan assets	(9)	(10)	(27)	(29)
Amortization of net loss (gain)	4	3	11	10
Net benefit expense (income)	5	4	15	12
Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost
Interest cost	1		1	1
Expected return on plan assets
Amortization of net loss (gain)	$ (1)		(2)	$ (1)
Net benefit expense (income)			$ (1)