Investments - OTTI (Details) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended				9 Months Ended				3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended				3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended				9 Months Ended				3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013 securities	Sep. 30, 2012 securities	Sep. 30, 2013 securities	Sep. 30, 2012 securities	Sep. 30, 2013 U.S. corporate securities	Sep. 30, 2012 U.S. corporate securities	Sep. 30, 2013 U.S. corporate securities	Sep. 30, 2012 U.S. corporate securities	Sep. 30, 2013 Foreign securities		Sep. 30, 2012 Foreign securities		Sep. 30, 2013 Foreign securities		Sep. 30, 2012 Foreign securities		Sep. 30, 2013 Residential mortgage-backed securities	Sep. 30, 2012 Residential mortgage-backed securities	Sep. 30, 2013 Residential mortgage-backed securities	Sep. 30, 2012 Residential mortgage-backed securities	Sep. 30, 2013 Commercial mortgage-backed securities	Sep. 30, 2012 Commercial mortgage-backed securities	Sep. 30, 2013 Commercial mortgage-backed securities	Sep. 30, 2012 Commercial mortgage-backed securities	Sep. 30, 2013 Other asset-backed securities securities	Sep. 30, 2012 Other asset-backed securities securities	Sep. 30, 2013 Other asset-backed securities securities	Sep. 30, 2012 Other asset-backed securities securities	Sep. 30, 2013 Equity securities securities	Sep. 30, 2012 Equity securities securities	Sep. 30, 2013 Equity securities securities	Sep. 30, 2012 Equity securities securities	Sep. 30, 2013 Fixed maturities	Dec. 31, 2012 Fixed maturities	Sep. 30, 2013 Intent related impairment securities	Sep. 30, 2012 Intent related impairment securities	Sep. 30, 2013 Intent related impairment securities	Sep. 30, 2012 Intent related impairment securities	Sep. 30, 2013 Intent related impairment U.S. corporate securities	Sep. 30, 2012 Intent related impairment U.S. corporate securities	Sep. 30, 2013 Intent related impairment U.S. corporate securities	Sep. 30, 2012 Intent related impairment U.S. corporate securities	Sep. 30, 2013 Intent related impairment Foreign securities		Sep. 30, 2012 Intent related impairment Foreign securities		Sep. 30, 2013 Intent related impairment Foreign securities		Sep. 30, 2012 Intent related impairment Foreign securities		Sep. 30, 2013 Intent related impairment Residential mortgage-backed securities	Sep. 30, 2012 Intent related impairment Residential mortgage-backed securities	Sep. 30, 2013 Intent related impairment Residential mortgage-backed securities	Sep. 30, 2012 Intent related impairment Residential mortgage-backed securities	Sep. 30, 2013 Intent related impairment Commercial mortgage-backed securities	Sep. 30, 2012 Intent related impairment Commercial mortgage-backed securities	Sep. 30, 2013 Intent related impairment Commercial mortgage-backed securities	Sep. 30, 2012 Intent related impairment Commercial mortgage-backed securities	Sep. 30, 2013 Intent related impairment Other asset-backed securities securities	Sep. 30, 2012 Intent related impairment Other asset-backed securities securities	Sep. 30, 2013 Intent related impairment Other asset-backed securities securities	Sep. 30, 2012 Intent related impairment Other asset-backed securities securities	Sep. 30, 2013 Credit related impairment	Sep. 30, 2012 Credit related impairment	Sep. 30, 2013 Credit related impairment	Sep. 30, 2012 Credit related impairment
Available-for-sale Securities Including Securities Pledged [Line Items]
Impairment	$ 800,000	$ 4,600,000	$ 2,700,000	$ 7,600,000	$ 0	$ 1,300,000	$ 0	$ 1,500,000	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 800,000	[1]	$ 400,000	$ 2,900,000	$ 2,200,000	$ 4,500,000	$ 100,000	$ 0	$ 200,000	$ 0	$ 200,000	$ 400,000	$ 200,000	$ 800,000	$ 100,000	$ 0	$ 100,000	$ 0
No. of Securities	17	27	37	39	0	1	0	2	0	[1]	0	[1]	0	[1]	3	[1]	14	23	32	30	1	0	3	0	1	3	1	4	1	0	1	0			3	0	5	5	0	0	0	1	0	[1]	0	[1]	0	[1]	3	[1]	2	0	2	0	1	0	3	0	0	0	0	1
Write-downs related to credit impairments																																																															700,000	4,600,000	2,500,000	6,500,000
Write-down related to intent impairments																																			100,000	0	200,000	1,100,000	0	0	0	200,000	0	[1]	0	[1]	0	[1]	800,000	[1]	0	0	0	0	100,000	0	200,000	0	0	0	0	100,000
Fair value of fixed maturies with OTTI																																	$ 1,800,000,000	$ 1,200,000,000

[1] Primarily U.S. dollar denominated.