Medium- And Long-Term Debt (Narrative) (Details) - Jun. 30, 2015 - USD ($) $ in Millions		Total
Debt Instrument [Line Items]
Blanket lien on real estate-related loans securing FHLB advances		$ 14,000
Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds		6,000
Subsidiaries | 2.50% notes due 2020
Debt Instrument [Line Items]
Notes issued	[1]	$ 500
Stated interest rate	[1]	2.50%

[1] The carrying value of medium- and long-term debt has been adjusted to reflect the gain or loss attributable to the risk hedged with interest rate swaps.