v3.7.0.1
Use of Collateral (Details) - USD ($)
$ in Millions
Jun. 30, 2017
Dec. 31, 2016
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Margin deposits [1] $ 248 $ 350
Natural gas and power prepayments 22 25
Total margin deposits and natural gas and power prepayments with our counterparties [2] 270 375
Letters of credit issued 743 798
First priority liens under power and natural gas agreements 195 206
First priority liens under interest rate hedging instruments 55 55
Total letters of credit and first priority liens with our counterparties 993 1,059
Margin deposits held by us posted by our counterparties [1],[3] 1 16
Letters of credit posted with us by our counterparties 27 43
Total margin deposits and letters of credit posted with us by our counterparties 28 59
Use of Collateral (Textuals) [Abstract]    
Margin And Prepayment Amounts Included In Other Assets 9 9
Margin And Prepayment Amounts Included In Margin Deposits And Other Prepaid Expenses $ 261 $ 366
[1] Balances are subject to master netting arrangements and presented on a gross basis on our Consolidated Condensed Balance Sheets. We do not offset fair value amounts recognized for derivative instruments executed with the same counterparty under a master netting arrangement for financial statement presentation, and we do not offset amounts recognized for the right to reclaim, or the obligation to return, cash collateral with corresponding derivative instrument fair values. See Note 6 for further discussion of our derivative instruments subject to master netting arrangements.
[2] At June 30, 2017 and December 31, 2016, $261 million and $366 million, respectively, were included in margin deposits and other prepaid expense and $9 million and $9 million, respectively, were included in other assets on our Consolidated Condensed Balance Sheets.
[3] Included in other current liabilities on our Consolidated Condensed Balance Sheets.