Marketable Investment Securities (Tables)

6 Months Ended

Dec. 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 debt securities classified as available-for-sale securities by major security type and class of security at December 31, 2020, June 30, 2020 and June 30, 2019 were as follows:


(in millions)	Amortized cost		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
December 31, 2020:
Cash and cash equivalents:
Cash	$	47.9	$	—	$	—	$	47.9
Cash equivalents	69.1		—		—		69.1
Total cash and cash equivalents	117.0		—		—		117.0
Available-for-sale:
Corporate bonds and notes	28.8		0.5		—		29.3
Municipal bonds	9.4		0.2		—		9.6
Federal agency issues	4.0		—		—		4.0
US government securities	11.7		0.1		—		11.8
Total	$	170.9	$	0.8	$	—	$	171.7


(in millions)	Amortized cost		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
June 30, 2020:
Cash and cash equivalents:
Cash	$	132.8	$	—	$	—	$	132.8
Cash equivalents	30.9		—		—		30.9
Total cash and cash equivalents	163.7		—		—		163.7
Available-for-sale:
Corporate bonds and notes	50.1		0.8		—		50.9
Municipal bonds	17.8		0.2		—		18.0
Federal agency issues	5.5		0.1		—		5.6
US government securities	16.4		0.2		—		16.6
Total	$	253.5	$	1.3	$	—	$	254.8


(in millions)	Amortized cost		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
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 Cash, Cash Equivalents, and Maturities of Debt Securities Classified as Available-For-Sale Securities

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


(in millions)	Amortized cost		Estimated fair value
Cash	47.9		47.9
Cash equivalents	69.1		69.1
Available-for-sale:
Due within one year	33.5		33.7
Due after one year through five years	20.4		21.0
Due after five years	—		—
Total	$	170.9	$	171.7