Business and Basis of Presentation - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended	6 Months Ended	0 Months Ended	9 Months Ended
	Oct. 09, 2014	Mar. 31, 2015	Jun. 30, 2014	Oct. 22, 2014	Mar. 31, 2015	Oct. 10, 2014	Oct. 20, 2014
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Stock split ratio	223,000
Common stock, shares outstanding		243,008,679	223,000,000		243,008,679	223,000,000
Debt issuance costs, net		$ (73.9)	$ (89.4)
IPO [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock shares issued as initial public offering				24,079,002	16,008,679
Shares Issued, Price Per Share				$ 19		19
Net proceeds from IPO, after deducting underwriting discounts and other offering expenses.				282.0	304.2
Purchase of additional shares from selling stockholder's by underwriters.							3,026,371
IPO [Member] | Parent Company
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock shares issued as initial public offering				16,008,679
IPO [Member] | Majority Shareholder
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock shares issued as initial public offering				8,070,323
Net proceeds from IPO, after deducting underwriting discounts and other offering expenses.				$ 150.2
Common Stock [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock, shares outstanding	223,000,000	243,008,679	223,000,000		243,008,679
Common stock shares issued as initial public offering					20,008,679