Basis of Presentation Basis of Presentation (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net Cash Provided by (Used in) Investing Activities			$ 3,548	$ 3,348
Cash Segregated under Commodity Exchange Act Regulation	$ 1,200		1,200
Net Cash Provided by (Used in) Operating Activities			(3,179)	(2,080)
Restricted Cash and Cash Equivalents	1,200	$ 1,457	1,200	1,457
Cash Flows Between Transferor and Transferee, Beneficial Interest			4,000	3,900
Other (Income) Expense - Net [Member]
Defined benefit plan net periodic benefit cost other than service cost	$ (2)	11	$ (5)	20
Cost of Products Sold [Member]
Defined benefit plan net periodic benefit cost other than service cost		5		9
Selling, General and Administrative Expenses [Member]
Defined benefit plan net periodic benefit cost other than service cost		6		11
Restatement Adjustment [Member]
Net Cash Provided by (Used in) Operating Activities				520
Restricted Cash and Cash Equivalents		$ 1,400		$ 1,400