Income Taxes (Reconciliation between the Company's federal income tax (expense) benefit at statutory rates and the recorded income tax (expense) benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax expense at statutory rates	$ (192)	$ (423)	$ (447)
Tax benefit from tax exempt income	123	119	97
Foreign taxes and credits	9	(6)	(1)
Other tax expense	(10)	(9)	(10)
Income tax (expense) benefit	$ (70)	$ (319)	$ (361)