Marketable Investment Securities (Tables)

9 Months Ended

Mar. 31, 2020

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 March 31, 2020 and June 30, 2019 were as follows:

			Gross		Gross
			unrealized		unrealized
	Amortized		holding		holding			Estimated
	cost		gains		losses			fair value
At March 31, 2020:
Cash and cash equivalents:
Cash	$	103.7	$	—	$	—		$	103.7
Cash equivalents		17.3		—		—		$	17.3
Total cash and cash equivalents		121.0		—		—			121.0
Available-for-sale:
Corporate bonds and notes		61.0		0.2		(0.2	)		61.0
Municipal bonds		19.9		0.1		—			20.0
Federal agency issues		5.5		0.1		—			5.6
US government securities		16.4		0.3		—			16.7
Total	$	223.8	$	0.7	$	(0.2	)	$	224.3

			Gross		Gross
			unrealized		unrealized
	Amortized		holding		holding		Estimated
	cost		gains		losses		fair value
At June 30, 2019:
Cash and cash equivalents:
Cash	$	68.7	$	—	$	—	$	68.7
Cash equivalents		24.5		—		—		24.5
Total cash and cash equivalents		93.2		—		—		93.2
Available-for-sale:
Corporate bonds and notes		64.0		0.6		—		64.6
Municipal bonds		15.3		—		—		15.3
Federal agency issues		9.0		—		—		9.0
US government securities		9.7		—		—		9.7
Total	$	191.2	$	0.6	$	—	$	191.8

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

Cash, cash equivalents, and maturities of debt securities classified as available-for-sale securities are as follows at March 31, 2020:

	Amortized		Estimated
	cost		fair value
Cash	$	103.7	$	103.7
Cash equivalents		17.3		17.3
Available-for-sale:
Due within one year		60.2		60.5
Due after one year through five years		42.6		42.8
Due after five years		—		—
Total	$	223.8	$	224.3