Compensation and Benefit Plans (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Pension and Other Postretirement Benefits
Additional plan year contributions			$ 44
Employer contributions			12
Pension Plans
Pension and Other Postretirement Benefits
Additional plan year contributions			69
Employer contributions			61
Expense components are:
Service cost	43	34	86	68
Interest cost	52	54	104	108
Expected return on plan assets	(60)	(52)	(120)	(104)
Amortization of prior service cost (credit)	2	2	4	4
Amortization of net loss	6	7	12	14
Expense under accounting standards	43	45	86	90
Regulatory adjustment - deferred	(6)	(14)	(12)	(28)
Total expense recognized	37	31	74	62
Postretirement Benefits Other Than Pensions
Expense components are:
Service cost	11	8	22	16
Interest cost	33	31	66	62
Expected return on plan assets	(28)	(25)	(56)	(50)
Amortization of prior service cost (credit)	(9)	(9)	(18)	(18)
Amortization of net loss	9	8	18	16
Total expense recognized	$ 16	$ 13	$ 32	$ 26