Investments and Derivative Instruments (Details Textual 1) (USD $)											3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014 International Program Hedging Instruments [Member]	Dec. 31, 2013 International Program Hedging Instruments [Member]	Mar. 31, 2014 Contingent Capital Facility Put Option [Member]	Dec. 31, 2013 Contingent Capital Facility Put Option [Member]	Mar. 31, 2014 Standard Market Indices of Diversified Portfolios [Member] Basket Credit Default Swaps [Member]	Dec. 31, 2013 Standard Market Indices of Diversified Portfolios [Member] Basket Credit Default Swaps [Member]	Mar. 31, 2014 Currency Options [Member] International Program Hedging Instruments [Member]	Dec. 31, 2013 Currency Options [Member] International Program Hedging Instruments [Member]	Mar. 31, 2014 3 Win Related Foreign Currency Swaps [Member] JAPAN	Mar. 31, 2013 3 Win Related Foreign Currency Swaps [Member] JAPAN	Mar. 31, 2014 Foreign Exchange Forward [Member] International Program Hedging Instruments [Member]	Dec. 31, 2013 Foreign Exchange Forward [Member] International Program Hedging Instruments [Member]	Mar. 31, 2014 Foreign Exchange Forward [Member] Net Hedge Position [Member] International Program Hedging Instruments [Member]	Dec. 31, 2013 Foreign Exchange Forward [Member] Net Hedge Position [Member] International Program Hedging Instruments [Member]	Mar. 31, 2014 Foreign Exchange Forward [Member] Long Hedge Position [Member] International Program Hedging Instruments [Member]	Dec. 31, 2013 Foreign Exchange Forward [Member] Long Hedge Position [Member] International Program Hedging Instruments [Member]	Mar. 31, 2014 Foreign Exchange Forward [Member] Short Hedge Position [Member] International Program Hedging Instruments [Member]	Dec. 31, 2013 Foreign Exchange Forward [Member] Short Hedge Position [Member] International Program Hedging Instruments [Member]
Derivative [Line Items]
Maximum aggregate principal amount of junior subordinated notes					$ 500
Associated liability adjusted for changes in spot rates through realized capital gain											(28,000,000)	116,000,000
Notional amount	141,307,000,000	159,441,000,000	61,528,000,000	73,048,000,000	500,000,000	500,000,000			5,432,000,000	12,066,000,000			15,474,000,000	13,410,000,000	(900,000,000)	(1,800,000,000)	7,300,000,000	5,800,000,000	8,200,000,000	7,600,000,000
Amount of standard market indices of diversified portfolios of corporate issuers							$ 4,100,000,000	$ 4,100,000,000