Marketable Investment Securities (Tables)

6 Months Ended

Dec. 31, 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 December 31, 2016 and June 30, 2016 were as follows:


	Amortized cost		Gross unrealized holding gains		Gross unrealized holding losses			Estimated fair value
At December 31, 2016:
Cash and cash equivalents:
Cash	$	81.3	$	—	$	—		$	81.3
Cash equivalents		26.8		—		—			26.8

Total cash and cash equivalents		108.1		—		—			108.1

Available-for-sale:
Corporate bonds and notes		38.6		—		(0.1	)		38.5
Municipal bonds		55.7		—		(0.1	)		55.6
Federal agency issues		12.6		—		(0.1	)		12.5
US government securities		3.3		—		—			3.3

Total	$	218.3	$	—	$	(0.3	)	$	218.0


	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

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 December 31, 2016:


	Amortized cost		Estimated fair value
Cash	$	81.3	$	81.3
Cash equivalents		26.8		26.8
Available-for-sale:
Due within one year		54.4		54.4
Due after one year through five years		55.8		55.5
Due after five years		—		—

Total	$	218.3	$	218.0