v2.4.0.6
Use of Collateral (Details) (USD $)
In Millions, unless otherwise specified
Mar. 31, 2013
Dec. 31, 2012
Use of Collateral [Abstract]    
Margin deposits $ 257 [1] $ 196 [1]
Natural gas and power prepayments 35 35
Total margin deposits and natural gas and power prepayments with our counterparties 292 [2] 231 [2]
Letters of credit issued 486 484
First priority liens under power and natural gas agreements 5 14
First priority liens under interest rate swap agreements 194 206
Total letters of credit and first priority liens with our counterparties 685 704
Margin deposits held by us posted by our counterparties 1 [1],[3] 11 [1],[3]
Letters of credit posted with us by our counterparties 2 1
Total margin deposits and letters of credit posted with us by our counterparties 3 12
Use of Collateral (Textuals) [Abstract]    
Margin And Prepayment Amounts Included In Other Assets 19 20
Margin And Prepayment Amounts Included In Margin Deposits And Other Prepaid Expenses $ 273 $ 211
[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.
[2] At March 31, 2013 and December 31, 2012, $273 million and $211 million, respectively, were included in margin deposits and other prepaid expense and $19 million and $20 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.