Accumulated Other Comprehensive Loss (Tables)
 6 Months Ended
Mar. 31, 2016
Statement of Comprehensive Income [Abstract]  
Schedule of Accumulated Other Comprehensive Loss
Changes in accumulated other comprehensive loss (AOCL), net of tax, by component for the three and six months ended March 31, 2016 and 2015 are as follows:
 
Foreign Exchange Translation Adjustment
 
Pension and Other Postretirement Adjustments (1)
 
Change in the Fair Value of Effective Cash Flow Hedges
 
Total
Balance at December 31, 2015
$
(64
)
 
$
(1,624
)
 
$
(5
)
 
$
(1,693
)
Other comprehensive income before reclassifications
8

 
—

 
—

 
8

Amounts reclassified from accumulated other comprehensive loss
—

 
13

 
2

 
15

Net current period other comprehensive income
8

 
13

 
2

 
23

Balance at March 31, 2016
$
(56
)
 
$
(1,611
)
 
$
(3
)
 
$
(1,670
)
 
 
 
 
 
 
 
 
Balance at September 30, 2015
$
(56
)
 
$
(1,637
)
 
$
(6
)
 
$
(1,699
)
Other comprehensive loss before reclassifications
—

 
—

 
(1
)
 
(1
)
Amounts reclassified from accumulated other comprehensive loss
—

 
26

 
4

 
30

Net current period other comprehensive income
—

 
26

 
3

 
29

Balance at March 31, 2016
$
(56
)
 
$
(1,611
)
 
$
(3
)
 
$
(1,670
)
 
 
 
 
 
 
 
 
Balance at December 31, 2014
$
(29
)
 
$
(1,337
)
 
$
(7
)
 
$
(1,373
)
Other comprehensive loss before reclassifications
(22
)
 
—

 
—

 
(22
)
Amounts reclassified from accumulated other comprehensive loss
—

 
12

 
1

 
13

Net current period other comprehensive income (loss)
(22
)
 
12

 
1

 
(9
)
Balance at March 31, 2015
$
(51
)
 
$
(1,325
)
 
$
(6
)
 
$
(1,382
)
 
 
 
 
 
 
 
 
Balance at September 30, 2014
$
(15
)
 
$
(1,348
)
 
$
(3
)
 
$
(1,366
)
Other comprehensive loss before reclassifications
(36
)
 
—

 
(5
)
 
(41
)
Amounts reclassified from accumulated other comprehensive loss
—

 
23

 
2

 
25

Net current period other comprehensive income (loss)
(36
)
 
23

 
(3
)
 
(16
)
Balance at March 31, 2015
$
(51
)
 
$
(1,325
)
 
$
(6
)
 
$
(1,382
)

(1) Reclassifications from AOCL to net income, related to the amortization of net actuarial losses and prior service credits for the Company's retirement benefit plans, were $21 million ($13 million net of tax) and $18 million ($12 million net of tax) for the three months ended March 31, 2016 and 2015, respectively, and were $42 million ($26 million net of tax) and $36 million ($23 million net of tax) for the six months ended March 31, 2016 and 2015, respectively. The reclassifications are included in the computation of net benefit expense. See Note 9, Retirement Benefits, for additional details.