Investments In And Advances To Affiliates (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) entity facility	Dec. 31, 2016 entity
Schedule Of Equity Method Investments [Line Items]
Amount of credit facility provided to unconsolidated affiliates	$ 78
Number of unconsolidated affiliates provided with credit facilities by the entity | entity	4
Number of credit facilities with outstanding balance | facility	3
Outstanding balance of credit facilities	$ 32
Due to Affiliate, Current	$ 79
Interest rate on due to affiliate, percentage	3.26%
Wilmar International Limited [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	24.90%	23.20%
Carrying value of direct investments	$ 3,800
Market value of direct investments	$ 3,600
Minimum [Member]
Schedule Of Equity Method Investments [Line Items]
Credit facility, basis spread on floating interest rate	3.74%
Maximum [Member]
Schedule Of Equity Method Investments [Line Items]
Credit facility, basis spread on floating interest rate	4.74%
Equity Method Investments [Member]
Schedule Of Equity Method Investments [Line Items]
Number of unconsolidated affiliates | entity	56	59
Undistributed earnings of unconsolidated affiliates	$ 2,100