Investments - Net Realized Gains on Sales of Investments (Details) - Fixed Maturities: - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Net Investment Income [Line Items]
Realized Gains	$ 15.1	$ 4.1
Realized Losses	$ (2.6)	$ (2.1)

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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