Income Taxes Textuals (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes (Textuals) [Line Items]
Unrecognized tax benefits change as a result of potential resolutions of prior years' tax	$ 3
U.S. statutory federal income tax rate	21.00%	35.00%	35.00%
Unrecognized tax benefits	$ 73	$ 24	$ 308	$ 211
Unrecognized tax benefits that effect effective tax rate	52	19	12
Unrecognized tax benefits income tax penalties and interest expense	0	1	2
Unrecognized tax benefits income tax penalties and interest accrued	5	5
Current federal taxes payable/receivable	727	786
Income tax paid/refund net	144	(308)
Tax positions related to prior years	0	(289)	$ (1)
U.S. Tax Act Discrete Tax (Benefit) charge	(23)	858
U.S. Tax Act Deemed Repatriation of Taxes		737
U.S. Tax Act Deferred Tax on distribution of foreign subs earnings	(25)	105
U.S. Tax Act Remeasurement Of Deferred Tax Assets and Liabilities		$ 16
Deemed Repatriation Tax Payments Due By Year Total	$ 731
Effective tax rate	7.00%	319.30%	7.10%
U.S. Tax Act Deemed Repatriation of Taxes Additional	$ 2
Tax Year 2018 [Member]
Income Taxes (Textuals) [Line Items]
U.S. statutory federal income tax rate	21.00%	21.00%
Twelve Month [Member]
Income Taxes (Textuals) [Line Items]
Unrecognized tax benefits that effect effective tax rate	$ 2
Internal Revenue Service (IRS) [Member] | Earliest Year [Member]
Income Tax Contingency [Line Items]
Open tax years by major tax jurisdiction	2015
Tax Audit Settlement Years	2008
Internal Revenue Service (IRS) [Member] | Latest Year [Member]
Income Tax Contingency [Line Items]
Tax Audit Settlement Years	2014