Retirement Benefit Liabilities
 6 Months Ended
Mar. 31, 2015
Compensation and Retirement Disclosure [Abstract]  
Retirement Benefit Liabilities
Retirement Benefit Liabilities
     Retirement benefit liabilities consisted of the following (in millions):
 
March 31,
2015
 
September 30,
2014
Retiree medical liability
$
468

 
$
479

Pension liability
297

 
323

Other
15

 
16

Subtotal
780

 
818

Less: current portion (included in compensation and benefits, Note 14)
(43
)
 
(43
)
Retirement benefits
$
737

 
$
775


The components of net periodic pension and retiree medical expense included in continuing operations for the three months ended March 31 are as follows (in millions):
 
2015
 
2014
 
Pension
 
Retiree Medical
 
Pension
 
Retiree Medical
Interest cost
18

 
5

 
20

 
7

Assumed return on plan assets
(28
)
 
—

 
(26
)
 
—

Amortization of prior service costs
—

 
—

 
—

 
(2
)
Recognized actuarial loss
7

 
5

 
6

 
5

Total expense (income)
$
(3
)
 
$
10

 
$
—

 
$
10



The components of net periodic pension and retiree medical expense included in continuing operations for the six months ended March 31 are as follows (in millions):
 
2015
 
2014
 
Pension
 
Retiree Medical
 
Pension
 
Retiree Medical
Interest cost
36

 
10

 
40

 
13

Assumed return on plan assets
(56
)
 
—

 
(52
)
 
—

Amortization of prior service costs
—

 
—

 
—

 
(4
)
Recognized actuarial loss
14

 
10

 
12

 
11

Total expense
$
(6
)
 
$
20

 
$
—

 
$
20