Stockholders' Equity and Statutory Accounting Practices (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Stockholders' Equity and Statutory Accounting Practices [Abstract]
Increase in statutory capital and surplus due to prescribed practice	$ 90
Statutory Accounting Practices, Statutory Amount Available for Dividend Payment Before Consideration of Statutory Dividends Paid in the preceding twelve months	$ 1,079
Capital Required for Capital Adequacy to Risk Weighted Assets	266.00%	270.00%
Statutory Accounting Practices, Dividends Paid in the preceding twelve months	$ 900