Income Taxes (Details Textuals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes (Textuals) [Abstract]
Unrecognized tax benefits as a result of potential resolutions of prior years' tax	$ 293
Unrecognized tax benefits, amounts recorded to equity	$ 289
U.S. statutory federal income tax rate	35.00%	35.00%	35.00%
Out of period tax adjustment		$ 11
Accumulated earnings intended to be permanently reinvested outside the U.S.	$ 4,900
Aggregate of federal taxes	1,700
Unrecognized tax benefits	308	211	$ 364	$ 481
Unrecognized tax benefits that effect effective tax rate	12	14	16
Unrecognized tax benefits income tax penalties and interest expense	2	1	$ 10
Unrecognized tax benefits income tax penalties and interest accrued	48	42
Current federal taxes payable/receivable	(18)	44
Income tax paid/refund net	45	$ 332
Tax benefit recognized in subsequent period	$ 289
Out of period tax rate adjustment		4.40%
Internal Revenue Service (IRS) [Member] | Earliest Year [Member]
Income Tax Contingency [Line Items]
Open tax years by major tax jurisdiction	2008
Internal Revenue Service (IRS) [Member] | Latest Year [Member]
Income Tax Contingency [Line Items]
Open tax years by major tax jurisdiction	2014