Acquisition (Details) (Cuprum, USD $)	0 Months Ended
	Feb. 04, 2013
Business Acquisition
Percent of principal shareholders ownership acquired (as a percent)	63.00%
Potential percent of publicly traded shares acquired (as a percent)	37.00%
Percent of business acquired (as a percent)	91.55%
Purchase price of acquired business	$ 1,300,000,000
Equity securities, available-for-sale	3,200,000
Equity securities, trading	340,500,000
Real estate	1,900,000
Other investments	24,200,000
Cash and cash equivalents	3,500,000
Premiums due and other receivables	1,400,000
Property and equipment	19,600,000
Goodwill	633,300,000
Other intangibles	671,300,000
Separate account assets	33,919,400,000
Other assets	27,300,000
Total assets acquired	35,645,600,000
Short-term debt	5,000,000
Long-term debt	114,600,000
Separate account liabilities	33,919,400,000
Other liabilities	229,500,000
Total liabilities assumed	34,268,500,000
Noncontrolling interest	113,600,000
Net assets acquired	1,263,500,000
Trade names
Business Acquisition
Acquired Indefinite-lived Intangible Asset, Amount	185,200,000
Customer relationships
Business Acquisition
Acquired Finite-lived Intangible Asset, Amount	$ 486,100,000
Acquired Finite-Lived Intangible Asset, Useful Life	15 years