Variable Interest Entities (Schedule Of Consolidated VIEs) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Restricted Receivables of VIEs	$ 1,157	$ 1,302
Other Current Assets	1,051	1,169
Intangibles, net	363	467
Restricted Other Assets of VIEs	135	139
Other Assets	2,231	2,291
Property, Plant and Equipment Cost, VIEs	913	942
Less Accumulated Depreciation and Amortization	(18,789)	(18,195)
Other Deferred Debits	153	133
Accounts payable	1,433	1,387
Non-Recourse Notes Payable	273	216
Taxes accrued	431	412
Current Maturities of Long-Term Debt	1,894	275
Other Current Liabilities	1,091	1,370
Non-Recourse Long-Term Debt	949	976
Deferred income taxes	7,581	6,978
Asset Retirement Obligation	1,936	1,816
Noncontrolling interests	93	131
Total common stockholder's equity	22,772	22,522
Consolidated VIEs [Member]
Restricted Receivables of VIEs	1,157	1,302
Other Current Assets	134	294
Intangibles, net	12	13
Restricted Other Assets of VIEs	135	139
Other Assets	50	23
Property, Plant and Equipment Cost, VIEs	913	942
Less Accumulated Depreciation and Amortization	(62)	(55)
Other Deferred Debits	26	21
Total Assets	2,365	2,679
Accounts payable	2	4
Non-Recourse Notes Payable	273	216
Taxes accrued	3	1
Current Maturities of Long-Term Debt	65	61
Other Current Liabilities	62	21
Non-Recourse Long-Term Debt	949	976
Deferred income taxes	160	191
Asset Retirement Obligation	13	12
Other Liabilities	50	26
Total Liabilities	1,577	1,508
Noncontrolling interests	1	1
Total common stockholder's equity	787	1,170
Consolidated VIEs [Member] | DERF [Member]
Restricted Receivables of VIEs	581	637
Other Current Assets
Intangibles, net
Restricted Other Assets of VIEs
Other Assets
Property, Plant and Equipment Cost, VIEs
Less Accumulated Depreciation and Amortization
Other Deferred Debits
Total Assets	581	637
Accounts payable
Non-Recourse Notes Payable
Taxes accrued
Current Maturities of Long-Term Debt
Other Current Liabilities
Non-Recourse Long-Term Debt	300	300
Deferred income taxes
Asset Retirement Obligation
Other Liabilities
Total Liabilities	300	300
Noncontrolling interests
Total common stockholder's equity	281	337
Consolidated VIEs [Member] | CRC [Member]
Restricted Receivables of VIEs	547	629
Other Current Assets
Intangibles, net
Restricted Other Assets of VIEs
Other Assets
Property, Plant and Equipment Cost, VIEs
Less Accumulated Depreciation and Amortization
Other Deferred Debits
Total Assets	547	629
Accounts payable
Non-Recourse Notes Payable	273	216
Taxes accrued
Current Maturities of Long-Term Debt
Other Current Liabilities
Non-Recourse Long-Term Debt
Deferred income taxes
Asset Retirement Obligation
Other Liabilities
Total Liabilities	273	216
Noncontrolling interests
Total common stockholder's equity	274	413
Consolidated VIEs [Member] | CinCap V [Member]
Restricted Receivables of VIEs	13	12
Other Current Assets	2	4
Intangibles, net
Restricted Other Assets of VIEs	65	76
Other Assets	14	23
Property, Plant and Equipment Cost, VIEs
Less Accumulated Depreciation and Amortization
Other Deferred Debits
Total Assets	94	115
Accounts payable
Non-Recourse Notes Payable
Taxes accrued
Current Maturities of Long-Term Debt	11	9
Other Current Liabilities	3	5
Non-Recourse Long-Term Debt	60	71
Deferred income taxes
Asset Retirement Obligation
Other Liabilities	13	22
Total Liabilities	87	107
Noncontrolling interests
Total common stockholder's equity	7	8
Consolidated VIEs [Member] | Renewables [Member]
Restricted Receivables of VIEs	13	20
Other Current Assets	124	282
Intangibles, net	12	13
Restricted Other Assets of VIEs	10	(2)
Other Assets	36
Property, Plant and Equipment Cost, VIEs	913	892
Less Accumulated Depreciation and Amortization	(62)	(26)
Other Deferred Debits	24	24
Total Assets	1,070	1,203
Accounts payable	1	2
Non-Recourse Notes Payable
Taxes accrued	3	1
Current Maturities of Long-Term Debt	49	45
Other Current Liabilities	59	16
Non-Recourse Long-Term Debt	528	518
Deferred income taxes	160	191
Asset Retirement Obligation	13	12
Other Liabilities	37	4
Total Liabilities	850	789
Noncontrolling interests
Total common stockholder's equity	220	414
Consolidated VIEs [Member] | Other VIEs [Member]
Restricted Receivables of VIEs	3	4
Other Current Assets	8	8
Intangibles, net
Restricted Other Assets of VIEs	60	65
Other Assets
Property, Plant and Equipment Cost, VIEs		50
Less Accumulated Depreciation and Amortization		(29)
Other Deferred Debits	2	(3)
Total Assets	73	95
Accounts payable	1	2
Non-Recourse Notes Payable
Taxes accrued
Current Maturities of Long-Term Debt	5	7
Other Current Liabilities
Non-Recourse Long-Term Debt	61	87
Deferred income taxes
Asset Retirement Obligation
Other Liabilities
Total Liabilities	67	96
Noncontrolling interests	1	1
Total common stockholder's equity	$ 5	$ (2)