Selected Quarterly Financial Information (unaudited) (Textuals) (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Net Loss(gain) from natural disaster, net of Insurance recoveries	$ 93.4	$ 7.1	$ 31.9	$ 46.4
Gain from insurance recoveries, net of losses incurred	$ 93.4	$ 7.1	$ 31.9	$ 46.4