Retirement Benefit Plans
 3 Months Ended
Apr. 29, 2017
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) and non-contributory supplemental pension plans were as follows:
 
Three Months Ended
($ in millions)
April 29,
2017
 
April 30,
2016
Primary Pension Plan
 
 
 
Service cost
$
11

 
$
14

Interest cost
37

 
38

Expected return on plan assets
(54
)
 
(54
)
Amortization of prior service cost/(credit)
2

 
2

Net periodic benefit expense/(income)
$
(4
)
 
$
—

 
 
 
 
Supplemental Pension Plans
 
 
 
Service cost
$
—

 
$
—

Interest cost
2

 
2

Amortization of prior service cost/(credit)
—

 
—

Net periodic benefit expense/(income)
$
2

 
$
2

 
 
 
 
Primary and Supplemental Pension Plans Total
 
 
 
Service cost
$
11

 
$
14

Interest cost
39

 
40

Expected return on plan assets
(54
)
 
(54
)
Amortization of prior service cost/(credit)
2

 
2

Net periodic benefit expense/(income)
$
(2
)
 
$
2


Additionally, the Company had net periodic postretirement income of $4 million, in the three months ended April 30, 2016 related to the Company's noncontributory postretirement medical and dental plan which was included in SG&A expense in the unaudited Interim Consolidated Statements of Operations. The postretirement medical and dental plan was terminated effective December 31, 2016.