Retirement Benefit Plans
 3 Months Ended
May 02, 2015
Retirement Benefit Plans [Abstract]  
Retirement Benefit Plans
Retirement Benefit Plans
The components of net periodic benefit expense/(income) for our non-contributory qualified defined benefit pension plan (Primary Pension Plan), non-contributory supplemental pension plans and contributory postretirement health and welfare plan were as follows:
 
Three Months Ended
($ in millions)
May 2,
2015
 
May 3,
2014
Primary Pension Plan
 
 
 
Service cost
$
17

 
$
15

Interest cost
49

 
53

Expected return on plan assets
(89
)
 
(87
)
Amortization of actuarial loss/(gain)
26

 
13

Amortization of prior service cost/(credit)
2

 
1

Net periodic benefit expense/(income)
$
5

 
$
(5
)
 
 
 
 
Supplemental Pension Plans
 
 
 
Service cost
$
—

 
$
—

Interest cost
2

 
2

Amortization of actuarial loss/(gain)
3

 
4

Amortization of prior service cost/(credit)
—

 
—

Net periodic benefit expense/(income)
$
5

 
$
6

 
 
 
 
Primary and Supplemental Pension Plans Total
 
 
 
Service cost
$
17

 
$
15

Interest cost
51

 
55

Expected return on plan assets
(89
)
 
(87
)
Amortization of actuarial loss/(gain)
29

 
17

Amortization of prior service cost/(credit)
2

 
1

Net periodic benefit expense/(income)
$
10

 
$
1

 
 
 
 
Postretirement Health and Welfare Plan
 
 
 
Service cost
$
—

 
$
—

Interest cost
—

 
—

Amortization of actuarial loss/(gain)
—

 
—

Amortization of prior service cost/(credit)
(2
)
 
(2
)
Net periodic benefit expense/(income)
$
(2
)
 
$
(2
)
 
 
 
 
Retirement Benefit Plans Total
 
 
 
Service cost
$
17

 
$
15

Interest cost
51

 
55

Expected return on plan assets
(89
)
 
(87
)
Amortization of actuarial loss/(gain)
29

 
17

Amortization of prior service cost/(credit)
—

 
(1
)
Net periodic benefit expense/(income)
$
8

 
$
(1
)

Net periodic benefit expense/(income) for our noncontributory postretirement health and welfare plan was predominantly included in SG&A expense in the unaudited Interim Consolidated Statements of Operations.

Defined Contribution Plans
Our defined contribution plans include a qualified Savings, Profit-Sharing and Stock Ownership Plan (401(k) plan), which includes a non-contributory retirement account, and a non-qualified contributory unfunded mirror savings plan offered to certain members of management. Total expense for our defined contribution plans for each of the first quarters of 2015 and 2014 was $13 million and $13 million, respectively, and was predominantly included in SG&A expenses in the unaudited Interim Consolidated Statements of Operations.