Restricted Securities Available For Sale (Tables)

12 Months Ended

Dec. 31, 2021

Investments, Debt and Equity Securities [Abstract]

Schedule Of Restricted Securities Available For Sale

Restricted securities available for sale consist of the following:

(In millions)	As of December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Corporate bonds	$	27.3	$	0.3	$	(0.2)	$	27.4
U.S. Government and agency securities	21.5		0.2		(0.1)		21.6
Asset-backed securities	12.9		—		(0.1)		12.8
Mortgage-backed securities	0.3		—		—		0.3
Total restricted securities available for sale	$	62.0	$	0.5	$	(0.4)	$	62.1
(In millions)	As of December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Corporate bonds	$	31.3	$	1.1	$	—	$	32.4
U.S. Government and agency securities	19.7		0.7		—		20.4
Asset-backed securities	12.7		0.2		—		12.9
Mortgage-backed securities	0.4		—		—		0.4
Total restricted securities available for sale	$	64.1	$	2.0	$	—	$	66.1

Schedule Of Restricted Securities Available For Sale By Aging Category

The fair value and gross unrealized losses for restricted securities available for sale, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, are as follows:

(In millions)	Securities Available for Sale with Gross Unrealized Losses as of December 31, 2021
	Less than 12 Months				12 Months or More
	Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses		Total Estimated Fair Value		Total Gross Unrealized Losses
Corporate bonds	$	15.0	$	(0.2)	$	1.3	$	—	$	16.3	$	(0.2)
U.S. Government and agency securities	10.1		(0.1)		—		—		10.1		(0.1)
Asset-backed securities	8.4		(0.1)		—		—		8.4		(0.1)
Mortgage-backed securities	—		—		—		—		—		—
Total restricted securities available for sale	$	33.5	$	(0.4)	$	1.3	$	—	$	34.8	$	(0.4)

(In millions)	Securities Available for Sale with Gross Unrealized Losses as of December 31, 2020
	Less than 12 Months				12 Months or More
	Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses		Total Estimated Fair Value		Total Gross Unrealized Losses
Corporate bonds	$	2.2	$	—	$	—	$	—	$	2.2	$	—
U.S. Government and agency securities	—		—		—		—		—		—
Asset-backed securities	—		—		—		—		—		—
Mortgage-backed securities	—		—		—		—		—		—
Total restricted securities available for sale	$	2.2	$	—	$	—	$	—	$	2.2	$	—

Schedule Of Cost And Estimated Fair Values Of Debt Securities By Contractual Maturity

The cost and estimated fair values of debt securities by contractual maturity were as follows (securities with multiple maturity dates are classified in the period of final maturity).  Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.

(In millions)	As of December 31,
	2021				2020
Contractual Maturity	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Within one year	$	2.9	$	3.0	$	1.1	$	1.1
Over one year to five years	56.9		57.0		58.1		60.0
Over five years to ten years	2.1		2.0		4.7		4.8
Over ten years	0.1		0.1		0.2		0.2
Total restricted securities available for sale	$	62.0	$	62.1	$	64.1	$	66.1