XML 25 R52.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Marketable Investment Securities - Schedule of Maturities of Debt Securities Classified as Cash Equivalents and Available-For-Sale Securities (Detail) - USD ($)
$ in Millions
Dec. 31, 2019
Jun. 30, 2019
Schedule of Available-for-sale Securities [Line Items]    
Cash and cash equivalents, Amortized cost $ 81.2 $ 93.2
Due within one year, Amortized cost 62.6  
Due after one year through five years, Amortized cost 44.8  
Due after five years, Amortized cost 0.0  
Total, Amortized cost 188.6 191.2
Due within one year, Estimated fair value 62.7  
Due after one year through five years, Estimated fair value 45.3  
Due after five years, Estimated fair value 0.0  
Total, Estimated fair value 189.2 191.8
Cash [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Cash and cash equivalents, Amortized cost 63.2 68.7
Cash equivalents, Estimated fair value 63.2 68.7
Cash Equivalents [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Cash and cash equivalents, Amortized cost 18.0 24.5
Cash equivalents, Estimated fair value $ 18.0 $ 24.5