Reinsurance (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Incurred and paid claims	$ 126.0	$ 1,911.0	$ 7,046.0	$ 9,640.0
Historical Average Claims Ratios, Period, Maximum			10 years
Hollenfels
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Claims IBNR	$ 833.0	$ 665.0	$ 11,724.0	$ 9,076.0