Income Tax (Provision for Income Tax from Continuing Operations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal	$ 40	$ 584	$ (56)
State and local	3	10	9
Foreign	634	556	779
Subtotal	677	1,150	732
Deferred:
Federal	(2,058)	701	1,597
State and local	0	0	(1)
Foreign	382	297	137
Subtotal	(1,676)	998	1,733
Current and Deferred:
Provision for income tax expense (benefit)	$ (999)	$ 2,148	$ 2,465