Pension and Postretirement Plans (Tables)

9 Months Ended

Oct. 31, 2015

Compensation and Retirement Disclosure [Abstract]

Components of Net Periodic Pension Benefit Cost and Postretirement Benefit Income

The following are the components of net periodic pension benefit cost and net periodic postretirement benefit income, which is recognized as part of SG&A expense:

	Pension Benefits								Postretirement Benefits
	Thirteen weeks				Thirty-nine weeks				Thirteen weeks				Thirty-nine weeks
	ended				ended				ended				ended
	October 31,		November 1,		October 31,		November 1,		October 31,		November 1,		October 31,		November 1,
($ in millions)	2015		2014		2015		2014		2015		2014		2015		2014
Service cost	$	5	$	3	$	13	$	11	$	—	$	—	$	—	$	—
Interest cost		6		7		18		21		—		—		1		—
Expected return on plan assets		(10)		(9)		(29)		(28)		—		—		—		—
Amortization of net loss (gain)		3		5		10		12		—		(1)		(1)		(2)
Net benefit expense (income)	$	4	$	6	$	12	$	16	$	—	$	(1)	$	—	$	(2)