Reinsurance (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Funds held under reinsurance agreements, liability	$ 3,900	$ 3,700
Reinsurance recoveries reported in insurance claims and policyholders' benefits reported on the Consolidated Statement of Operations	1,527	1,514	1,285
Ceded claim and claim adjustment expense reserves, future policy benefits and policyholder funds as the result of business operations sold in prior years	1,066	1,131
Subsidiaries of Berkshire Hathaway Group [Member]
Largest Recoverables From Single Reinsurer	2,900
Subsidiaries of Swiss Re Group [Member]
Largest Recoverables From Single Reinsurer	850
Subsidiaries of Hartford Insurance Group [Member]
Largest Recoverables From Single Reinsurer	350
Significant Captive Program [Member]
Direct and ceded earned premiums	2,156	1,794	1,500
Reinsurance recoveries reported in insurance claims and policyholders' benefits reported on the Consolidated Statement of Operations	$ 712	$ 814	$ 790