Marketable Investment Securities

12 Months Ended

Jun. 30, 2017

Investments Debt And Equity Securities [Abstract]

Marketable Investment Securities

3. MARKETABLE INVESTMENT SECURITIES

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, 2017 and 2016 were as follows:

			Gross		Gross
			unrealized		unrealized
	Amortized		holding		holding			Estimated
	cost		gains		losses			fair value
At June 30, 2017:
Cash and cash equivalents:
Cash	$	83.5	$	—	$	—		$	83.5
Cash equivalents		18.9		—		—			18.9
Total cash and cash equivalents		102.4		—		—			102.4
Available-for-sale:
Corporate bonds and notes		45.4		0.1		(0.1	)		45.4
Municipal bonds		32.7		—		—			32.7
Federal agency issues		11.6		—		(0.1	)		11.5
US government securities		7.2		—		—			7.2
Total	$	199.3	$	0.1	$	(0.2	)	$	199.2

			Gross		Gross
			unrealized		unrealized
	Amortized		holding		holding		Estimated
	cost		gains		losses		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

Cash, cash equivalents, and maturities of debt securities classified as available-for-sale are as follows at June 30, 2017:

	Amortized		Estimated
	cost		fair value
Cash	$	83.5	$	83.5
Cash equivalents		18.9		18.9
Available-for-sale:
Due within one year		48.3		48.3
Due after one year through five years		48.6		48.5
Due after five years		—		—
Total	$	199.3	$	199.2

Debt securities in an unrealized loss position as of June 30, 2017 were not impaired at acquisition and the declines in fair value are not attributed to declines in credit quality. Management believes that it is more likely than not that the securities will be held until a recovery of par value. All securities in an unrealized loss position as of June 30, 2017 and 2016 are debt securities. Debt securities available-for-sale in a gross unrealized loss position as of June 30, 2017 and 2016 are summarized as follows:

	Less than 12 months				More than 12 months				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	value		losses		value		losses		value		losses
At June 30, 2017:
Debt securities:
Corporate bonds and notes		29.9		0.1		—		—		29.9		0.1
Municipal bonds		13.3		—		0.7		—		14.0		—
Federal agency issues		11.5		0.1		—		—		11.5		0.1
US government securities		5.3		—		—		—		5.3		—
	$	60.0	$	0.2	$	0.7	$	—	$	60.7	$	0.2

	Less than 12 months				More than 12 months				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	value		losses		value		losses		value		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	$	—

Additional information relating to fair value of marketable investment securities can be found in Note 12.