Derivative and Hedging Activities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Interest Rate Swaps
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	$ 1.2
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss)	(14.3)	$ (0.8)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(3.6)	(0.1)
Other Comprehensive Income (Loss), Cash Flow Hedge, Reclassification for Discontinuance, before Tax	10.4
Cash Flow Hedging [Member]
Interest Rate Swaps
Derivative, Fair Value, Net	$ 1.2	$ 0.1