Retirement Benefits
 6 Months Ended
Mar. 31, 2016
Compensation and Retirement Disclosure [Abstract]  
Retirement Benefits
Retirement Benefits

The Company sponsors defined benefit pension (Pension Benefits) and other postretirement (Other Retirement Benefits) plans which provide monthly pension and other benefits to eligible employees upon retirement.

Components of Expense (Income)
The components of expense (income) for Pension Benefits and Other Retirement Benefits for the three and six months ended March 31, 2016 and 2015 are summarized as follows:
 
Pension Benefits
 
Other Retirement Benefits
 
Three Months Ended
 
Three Months Ended
 
March 31
 
March 31
(in millions)
2016
 
2015
 
2016
 
2015
Service cost
$
3

 
$
3

 
$
1

 
$
1

Interest cost
31

 
39

 
2

 
3

Expected return on plan assets
(59
)
 
(61
)
 
(1
)
 
(1
)
Amortization:
 
 
 

 
 
 
 

Prior service credit
(1
)
 
—

 
—

 
(1
)
Net actuarial loss
20

 
18

 
2

 
1

Net benefit expense (income)
$
(6
)
 
$
(1
)
 
$
4

 
$
3


 
Pension Benefits
 
Other Retirement Benefits
 
Six Months Ended
 
Six Months Ended
 
March 31
 
March 31
(in millions)
2016
 
2015
 
2016
 
2015
Service cost
$
6

 
$
6

 
$
1

 
$
1

Interest cost
63

 
78

 
3

 
4

Expected return on plan assets
(119
)
 
(121
)
 
(1
)
 
(1
)
Amortization:
 
 
 
 
 
 
 
Prior service credit
(1
)
 
(1
)
 
—

 
(2
)
Net actuarial loss
39

 
36

 
4

 
3

Net benefit expense (income)
$
(12
)
 
$
(2
)
 
$
7

 
$
5


Prior to 2016, the Company used a single-weighted average discount rate to calculate pension interest and service cost. Beginning in 2016, a "spot rate approach" is being used to calculate pension interest and service cost. The spot rate approach applies separate discount rates for each projected benefit payment in the calculation of pension interest and service cost. This calculation change is considered a change in accounting estimate and is being applied prospectively in 2016. For the three and six months ended March 31, 2016, the use of the spot rate approach resulted in an increase to pension income and pre-tax earnings of $9 million and $18 million, respectively, relative to the estimated pension income amount had the Company not changed its approach.

In October 2014, the Society of Actuaries published a new set of mortality tables (RP-2014) and a new mortality improvement scale (MP-2014), which update life expectancy assumptions. The newly published tables generally reflect longer life expectancy than was projected by past tables. For the Company's 2015 year-end pension liability valuation, the Company used the RP-2014 tables with an adjustment for plan experience and the MP-2014 improvement scale adjusted to reflect convergence to an ultimate annual rate of mortality improvement of 0.75 percent by 2022. For the three and six months ended March 31, 2016, these changes resulted in a decrease to pension income and pre-tax earnings of $4 million and $8 million, respectively, relative to the estimated pension income amount had the Company not used new mortality table and improvement scale assumptions.

Pension Plan Funding
The Company’s objective with respect to the funding of its pension plans is to provide adequate assets for the payment of future benefits. Pursuant to this objective, the Company will fund its pension plans as required by governmental regulations and may consider discretionary contributions as conditions warrant. In October 2015, the Company voluntarily contributed $55 million to its U.S. qualified pension plans. There is no minimum statutory funding requirement for 2016 and the Company does not currently expect to make any additional discretionary contributions during 2016 to its U.S. qualified pension plans. Any additional future contributions necessary to satisfy minimum statutory funding requirements are dependent upon actual plan asset returns, interest rates and actuarial assumptions. Contributions to the non-U.S. plans and the U.S. non-qualified pension plan are expected to total $13 million in 2016. During the six months ended March 31, 2016, the Company made contributions to the non-U.S. plans and the U.S. non-qualified pension plan of $8 million.