Represents the total of interest and dividend income, including any amortization and accretion (as applicable) of discounts and premiums, earned from (1) loans and leases whether held-for-sale or held-in-portfolio; (2) investment securities; (3) federal funds sold; (4) securities purchased under agreements to resell; (5) investments in banker's acceptances, commercial paper, or certificates of deposit; (6) dividend income; or (7) other investments not otherwise specified herein.

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-Name Accounting Standards Codification

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Amount of expenses related to the generation of investment income.

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Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Investment Securities (Net Investment Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Investment income
Total investment income	$ 27.1	$ 29.5
Third-party investment expenses	(3.8)	(4.8)
Net investment income, pre-tax	23.3us-gaap_NetInvestmentIncome	24.7us-gaap_NetInvestmentIncome	24.7us-gaap_NetInvestmentIncome
Fixed maturity investments.
Investment income
Total investment income	23.1	22.4
Short-term investments
Investment income
Total investment income	0.6	0.6
Common Stock
Investment income
Total investment income	3.4	5.4
Convertible fixed maturity investments
Investment income
Total investment income	0.2	0.4
Other long-term investments
Investment income
Total investment income	(0.1)	0.7
Funds Held under Reinsurance Agreements [Member]
Investment income
Total investment income	$ (0.1)	$ 0