XML 133 R79.htm IDEA: XBRL DOCUMENT v3.5.0.2
Risk Management Activities and Derivative Transactions Risk Management Activities and Derivative Transactions - Derivative Instruments That Receive Hedge Accounting Treatment (Details) - USD ($)
12 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2014
Summary of Derivative Instruments That Receive Hedge Accounting Treatment      
Net unrealized gain (loss) on future cash flow hedges $ (139,000,000) $ (72,000,000) $ 4,000,000
Reclassification to earnings from cash flow hedges 129,000,000 65,000,000 $ (2,000,000)
Ineffective portion excluded from testing 0 $ 0  
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred $ 19,000,000