Income Taxes Components of Income Tax Provision (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Components of income tax provision [Line Items]
Current Federal Tax Expense (Benefit)	$ 562	$ 129	$ 667
Current State and Local Tax Expense (Benefit)	73	59	27
Current Income Tax Expense (Benefit)	635	188	694
Deferred Federal Income Tax Expense (Benefit)	(122)	275	59
Deferred State and Local Income Tax Expense (Benefit)	35	69	52
Deferred Income Tax Expense (Benefit)	(87)	344	111
Income Tax Expense (Benefit)	$ 548	$ 532	$ 805