Accounts and Unbilled Receivables - Accounts Receivable and Unbilled Receivables (Details) - USD ($)
$ in Millions
Jun. 30, 2017
Jun. 30, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Gross accounts receivable $ 580.0 $ 505.6
Provision for sales returns and credit losses (3.7) (2.6)
Total accounts receivable, net 576.3 503.0
Unbilled accounts receivable, net 159.8 135.7
Unbilled Revenues [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Provision for sales returns and credit losses (0.8) (1.2)
Gross accounts receivable $ 160.6 $ 136.9