Restructuring and Asset Impairment Charges (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Mar. 31, 2016
Dec. 31, 2015
Mar. 31, 2015
Mar. 31, 2016
Mar. 31, 2015
Restructuring and Asset Impairment Charges [Line Items]          
Employee separation costs   $ 39      
Asset impairment charges   6      
Restructuring and asset impairment charges $ 0 45 $ 0 $ 45 $ 0
Cost of Sales [Member]          
Restructuring and Asset Impairment Charges [Line Items]          
Employee separation costs   31      
Asset impairment charges   2      
Restructuring and asset impairment charges   33      
Selling, General and Administrative Expenses [Member]          
Restructuring and Asset Impairment Charges [Line Items]          
Employee separation costs   8      
Asset impairment charges   4      
Restructuring and asset impairment charges   12      
Special Termination Benefits [Member]          
Restructuring and Asset Impairment Charges [Line Items]          
Cash payments for employee separation costs 33 $ 5      
Restructuring reserve $ 1     $ 1