Restricted Securities Available For Sale (Restricted Securities Available For Sale) (Details) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost		$ 94.6	$ 76.1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax		0.6	0.0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		2.0	3.8
Debt Securities, Available-for-sale, Restricted	[1]	93.2	72.3
Corporate bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost		40.5	32.6
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax		0.3	0.0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		0.9	1.7
Debt Securities, Available-for-sale, Restricted		39.9	30.9
US Government and agency securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost		35.2	29.5
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax		0.2	0.0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		0.9	1.7
Debt Securities, Available-for-sale, Restricted		34.5	27.8
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost		18.0	13.8
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax		0.1	0.0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		0.2	0.4
Debt Securities, Available-for-sale, Restricted		17.9	13.4
Municipal securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost		0.7
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax		0.0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		0.0
Debt Securities, Available-for-sale, Restricted		0.7
Mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost		0.2	0.2
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax		0.0	0.0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		0.0	0.0
Debt Securities, Available-for-sale, Restricted		$ 0.2	$ 0.2

[1] Measured at fair value on a recurring basis.