Marketable Investment Securities (Tables)

12 Months Ended

Jun. 30, 2016

Investments, Debt and Equity Securities [Abstract]

Schedule of Fair Value for Available-for-Sale Securities by Major Security Type and Class of Security

The amortized cost, gross unrealized holding gains, gross unrealized holding losses, and fair value for available-for-sale securities by major security type and class of security at June 30, 2016 and 2015 were as follows:


	Amortized cost		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
At June 30, 2016:
Cash and cash equivalents:
Cash	$	66.1	$	—	$	—	$	66.1
Cash equivalents		2.4		—		—		2.4

Total cash and cash equivalents		68.5		—		—		68.5

Available-for-sale:
Corporate bonds and notes		50.8		0.2		—		51.0
Municipal bonds		85.4		0.2		—		85.6
Federal agency issues		25.5		—		—		25.5
US government securities		8.2		0.1		—		8.3

Total	$	238.4	$	0.5	$	—	$	238.9


	Amortized cost		Gross unrealized holding gains		Gross unrealized holding losses			Estimated fair value
At June 30, 2015:
Cash and cash equivalents:
Cash	$	54.7	$	—	$	—		$	54.7
Cash equivalents		9.4		—		—			9.4

Total cash and cash equivalents		64.1		—		—			64.1

Available-for-sale:
Corporate bonds and notes		41.8		—		—			41.8
Municipal bonds		66.3		0.1		(0.1	)		66.3
Federal agency issues		13.2		—		—			13.2
US government securities		—		—		—			—

Total	$	185.4	$	0.1	$	(0.1	)	$	185.4

Schedule of Maturities of Debt Securities Classified as Cash Equivalents and Available-For-Sale

Cash, cash equivalents, and maturities of debt securities classified as available-for-sale are as follows at June 30, 2016:


	Amortized cost		Estimated fair value
Cash	$	66.1	$	66.1
Cash equivalents		2.4		2.4
Available-for-sale:
Due within one year		90.5		90.5
Due after one year through five years		79.4		79.9
Due after five years		—		—

Total	$	238.4	$	238.9

Schedule of Debt Securities Available-For-Sale in Gross Unrealized Loss Position

Debt securities available-for-sale in a gross unrealized loss position as of June 30, 2016 and 2015 are summarized as follows:


	Less than 12 months					More than 12 months				Total
	Fair value		Unrealized losses			Fair value		Unrealized losses		Fair value		Unrealized losses
At June 30, 2016:
Debt securities:
Corporate bonds and notes		5.0		—			1.5		—		6.5		—
Municipal bonds		7.6		—			6.3		—		13.9		—
Federal agency issues		6.0		—			—		—		6.0		—
US government securities		—		—			—		—		—		—

	$	18.6	$	—		$	7.8	$	—	$	26.4	$	—


	Less than 12 months					More than 12 months				Total
	Fair value		Unrealized losses			Fair value		Unrealized losses		Fair value		Unrealized losses
At June 30, 2015:
Debt securities:
Corporate bonds and notes		24.4		(0.0	)		—		—		24.4		(0.0	)
Municipal bonds		24.8		(0.1	)		—		—		24.8		(0.1	)
Federal agency issues		1.9		(0.0	)		—		—		1.9		(0.0	)

	$	51.1	$	(0.1	)	$	—	$	—	$	51.1	$	(0.1	)