Restricted Securities Available For Sale (Tables)

9 Months Ended

Sep. 30, 2014

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 September 30, 2014
	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
U.S. Government and agency securities	$	31.6	$	—	$	(0.1	)	$	31.5
Corporate bonds	16.5		—		(0.1		)	16.4
Asset backed securities	2.8		—		—			2.8
Certificates of deposit	0.7		—		—			0.7
Total restricted securities available for sale	$	51.6	$	—	$	(0.2	)	$	51.4
(In millions)	As of December 31, 2013
	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Commercial paper	$	23.9	$	—	$	—		$	23.9
U.S. Government and agency securities	22.3		—		(0.2		)	22.1
Certificates of deposit	4.6		—		—			4.6
Corporate bonds	3.1		—		(0.1		)	3.0
Total restricted securities available for sale	$	53.9	$	—	$	(0.3	)	$	53.6

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 September 30, 2014
	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
U.S. Government and agency securities	$	20.8	$	(0.1	)	$	4.3	$	—		$	25.1	$	(0.1	)
Corporate bonds	12.1		—			2.7		(0.1		)	14.8		(0.1		)
Asset backed securities	1.6		—			—		—			1.6		—
Total restricted securities available for sale	$	34.5	$	(0.1	)	$	7.0	$	(0.1	)	$	41.5	$	(0.2	)

(In millions)	Securities Available for Sale with Gross Unrealized Losses as of December 31, 2013
	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
Commercial paper	$	10.0	$	—		$	—	$	—	$	10.0	$	—
U.S. Government and agency securities	11.8		(0.2		)	—		—		11.8		(0.2		)
Certificates of deposit	1.9		—			—		—		1.9		—
Corporate bonds	2.3		(0.1		)	—		—		2.3		(0.1		)
Total restricted securities available for sale	$	26.0	$	(0.3	)	$	—	$	—	$	26.0	$	(0.3	)

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
	September 30, 2014				December 31, 2013
	Cost		Estimated Fair Value		Cost		Estimated Fair Value
Contractual Maturity
Within one year	$	5.8	$	5.8	$	41.6	$	41.6
Over one year to five years	42.6		42.5		7.8		7.8
Over five years to ten years	3.2		3.1		4.5		4.2
Total restricted securities available for sale	$	51.6	$	51.4	$	53.9	$	53.6