Restricted Securities Available For Sale (Schedule Of Restricted Securities Available For Sale By Aging Category) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 33.5	$ 2.2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1.3	0.0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0.4	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	34.8	2.2
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	0.4	0.0
Corporate bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	15.0	2.2
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1.3	0.0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0.2	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	16.3	2.2
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	0.2	0.0
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	10.1	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	0.1	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	10.1	0.0
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	0.1	0.0
Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	8.4	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	0.1	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	8.4	0.0
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	0.1	0.0
Mortgage-backed securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	0.0	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	0.0	0.0
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 0.0	$ 0.0

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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