Financial Derivatives (Credit Default Swaps) (Details) (Credit Default Swap, Buying Protection [Member], USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Credit Derivatives [Line Items]
Notional Amount	$ 110	$ 95
Fair Value	(1)
Average term of credit risk derivatives	21 years 9 months	24 years 11 months
Underlying Other Beneficiary Single Name [Member]
Credit Derivatives [Line Items]
Notional Amount	50	35
Fair Value	(1)
Average term of credit risk derivatives	6 years 3 months	7 years 4 months
Underlying Other Beneficiary Index Traded [Member]
Credit Derivatives [Line Items]
Notional Amount	$ 60	$ 60
Average term of credit risk derivatives	34 years 9 months	35 years 2 months