Postretirement Health Care and Life Insurance Benefits (Net Periodic Benefit Cost) (Details) - Other Postretirement Benefit Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Jan. 30, 2016	Jan. 31, 2015	Feb. 01, 2014
Service cost	$ 0	$ 0	$ 0
Interest cost	8	10	10
Amortization of net actuarial (gain) loss	0	(5)	(3)
Amortization of prior service credit	0	0	0
Total net periodic benefit cost	8	5	7
Net actuarial (gain) loss recognized in OCI before tax	(22)	30	(15)
Amortization of net actuarial loss	0	5	3
Amortization of prior service credit	0	0	0
Total recognized in other comprehensive income	(22)	35	(12)
Total recognized in net periodic benefit cost and other comprehensive income	$ (14)	$ 40	$ (5)