Derivative Financial Instruments (Summary of aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments) (Details) (Not Designated as Hedging Instrument [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Derivative [Line Items]
Contractual/notional amount		$ 84
Estimated fair value asset
Estimated fair value (liability)		(3)
Credit default swap - purchased protection [Member]
Derivative [Line Items]
Contractual/notional amount		20
Estimated fair value asset
Estimated fair value (liability)		(1)
Currency forwards [Member]
Derivative [Line Items]
Contractual/notional amount		59
Estimated fair value asset
Estimated fair value (liability)		(2)
Equity warrants [Member]
Derivative [Line Items]
Contractual/notional amount	5	5
Estimated fair value asset
Estimated fair value (liability)