Restricted Securities Available For Sale (Schedule Of Restricted Securities Available For Sale By Aging Category) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 40.0	$ 33.5
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	26.9	1.3
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	1.5	0.4
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	2.3	0.0
Debt Securities, Available-for-sale, Unrealized Loss Position	66.9	34.8
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	3.8	0.4
Corporate bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	15.1	15.0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	13.3	1.3
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0.6	0.2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	1.1	0.0
Debt Securities, Available-for-sale, Unrealized Loss Position	28.4	16.3
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	1.7	0.2
US Government and agency securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	18.0	10.1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	9.2	0.0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0.8	0.1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0.9	0.0
Debt Securities, Available-for-sale, Unrealized Loss Position	27.2	10.1
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	1.7	0.1
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	6.6	8.4
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	4.4	0.0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0.1	0.1
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0.3	0.0
Debt Securities, Available-for-sale, Unrealized Loss Position	11.0	8.4
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	0.4	0.1
Mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	0.3	0.0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0.0	0.0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0.0	0.0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0.0	0.0
Debt Securities, Available-for-sale, Unrealized Loss Position	0.3	0.0
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 0.0	$ 0.0