Acquisition of Business - Pro Forma Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Business Combination and Asset Acquisition [Abstract]
Total Revenues	$ 1,507.7	$ 1,332.8	$ 2,950.9	$ 2,643.3
Total Expenses	1,597.1	1,159.4	2,901.2	2,399.1
Net Income	(89.4)	173.4	49.7	244.2
Business Acquisition, Pro Forma Income (Loss) from Continuing Operations, Net of Tax	$ (62.4)	$ 139.1	$ 74.3	$ 198.5