Income Taxes (Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Federal
Current	$ 6	$ (32)	$ 2
Deferred	0	41	836
Total	6	9	838
State and local
Current	(1)	(14)	2
Deferred	(23)	2	8
Total	(24)	(12)	10
Foreign
Current	274	483	91
Deferred	75	(104)	(16)
Total	349	379	75
Total
Current	279	437	95
Deferred	52	(61)	828
Total income tax expense (benefit)	$ 331	$ 376	$ 923