Compensation and Benefit Plans (Textual) (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Aug. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Accumulated Other Comprehensive Income Net Gains (Losses), after Tax	$ 0	$ (3)
Actuarial gain (loss)		$ (374)
Percentage of Premium Included in Estimated Rate of Return of Equity Securities	5.00%
Percentage of Premium Included in Estimated Rate of Return of Public Equity and Hedge Funds	2.00%
Performance incentive plan award, shares	49.5
Share-based compensation, shares available for grant	18.0
Employee Stock Option
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Stock options, expiration period, years	10 years
Stock options, vesting period, years	4 years
Period of Historical Volatility Used to Compute Expected Volatility	71 months	72 months	74 months
Performance shares
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Stock options, vesting period, years	3 years
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	$ (96)	$ (102)
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	123
Actuarial gain (loss)	149	(469)
Defined benefit obligation increase (decrease) during the period	$ (34)	$ 214
Discount rate, percent	4.18%	3.85%	4.75%	4.00%
Permissible range of asset class weights, percent	3.00%
Allocation of publicly traded equity investments, percent	63.00%	65.00%
Pension Plans | Non-US Equities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	17.00%
Pension Plans | US Equities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	29.00%
Pension Plans | Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	35.00%
Pension Plans | Opportunistic Alternative Investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	15.00%
Pension Plans | Other Investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	4.00%
Voluntary Employee Beneficiary Association (VEBA) | Non-US Equities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	5.00%
Voluntary Employee Beneficiary Association (VEBA) | Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	85.00%
Voluntary Employee Beneficiary Association (VEBA) | Opportunistic Alternative Investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	10.00%
Postretirement Benefits Other Than Pensions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	$ 33
Actuarial gain (loss)	500	$ (582)
Defined Benefit Plan, Experience Gain	300
Defined Benefit Plan, Change in Discount Rate	140
Defined benefit obligation increase (decrease) during the period	$ (62)	$ 308
Discount rate, percent	4.55%	4.16%
Defined Benefit Plan, Eligibility Age	55 years
Defined Benefit Plan, Minimum Service Period for Eligibility	10 years
Allocation of publicly traded equity investments, percent	71.00%
Postretirement Benefits Other Than Pensions | Non-US Equities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	17.00%
Postretirement Benefits Other Than Pensions | US Equities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	41.00%
Postretirement Benefits Other Than Pensions | Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	34.00%
Postretirement Benefits Other Than Pensions | Opportunistic Alternative Investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	7.00%
Postretirement Benefits Other Than Pensions | Other Investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target plan asset allocations, percent	1.00%
Southern California Edison
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial gain (loss)		$ (357)
Southern California Edison | Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	$ (27)	(31)
Defined Benefit Plan, Accumulated Other Comprehensive Income Net Gains (Losses), after Tax	18	22
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	94
Actuarial gain (loss)	143	(386)
Defined benefit obligation increase (decrease) during the period	$ (31)	$ 199
Discount rate, percent	4.18%	3.85%
Southern California Edison | Postretirement Benefits Other Than Pensions
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial gain (loss)	$ 500	$ (582)
Defined benefit obligation increase (decrease) during the period	$ (61)	$ 307
Discount rate, percent	4.55%	4.16%