Investments Low Income Housing Tax Credits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Investments, All Other Investments [Abstract]
Low Income Housing Tax Credits	$ 9.4	$ 10.3	$ 18.8	$ 20.7
Amortization of Low Income Housing Investments	(6.1)	(7.0)	(12.9)	(14.0)
Tax Benefits from Low Income Housing Investments	$ 3.3	$ 3.3	$ 5.9	$ 6.7