NORTHROP GRUMMAN CORP /DE/ | 2013 | FY | 3

The cost to the company of its retirement benefit plans in each of the three years ended December 31 is shown in the following table:
 
 
Year Ended December 31
 
 
Pension Benefits
 
Medical and
Life Benefits
$ in millions
 
2013
 
2012
 
2011
 
2013
 
2012
 
2011
Components of net periodic benefit cost
 
 
 
 
 
 
 
 
 
 
 
 
Service cost
 

$ 516

 

$ 522

 

$ 520

 

$ 36

 

$ 34

 

$ 32

Interest cost
 
1,117

 
1,184

 
1,223

 
96

 
109

 
114

Expected return on plan assets
 
(1,809
)
 
(1,708
)
 
(1,690
)
 
(75
)
 
(68
)
 
(62
)
Amortization of:
 
 
 
 
 
 
 
 
 
 
 
 
Prior service (credit) cost
 
(58
)
 
(58
)
 
23

 
(51
)
 
(51
)
 
(51
)
Net loss from previous years
 
608

 
427

 
162

 
30

 
21

 
17

Other
 
—

 
7

 
—

 
—

 
—

 
(6
)
Net periodic benefit cost
 

$ 374

 

$ 374

 

$ 238

 

$ 36

 

$ 45

 

$ 44

us-gaap:ScheduleOfCostsOfRetirementPlansTableTextBlock