Debt - Long-term Debt (Detail) - USD ($) $ in Millions		Sep. 30, 2016	Mar. 11, 2016	Feb. 16, 2016	Sep. 30, 2015
Debt Instrument [Line Items]
Total debt		$ 2,812			$ 2,994
Less: current portion					13
Total long-term debt	[1]	2,812			2,981
Acquisition Corp. | Senior Term Loan Facility due 2020
Debt Instrument [Line Items]
Total debt	[2]	975			1,282
Less: current portion					13
Acquisition Corp. | 5.625% Senior Secured Notes due 2022
Debt Instrument [Line Items]
Total debt		275			275
Acquisition Corp. | 6.00% Senior Secured Notes due 2021
Debt Instrument [Line Items]
Total debt		450			450
Acquisition Corp. | 6.25% Senior Secured Notes due 2021
Debt Instrument [Line Items]
Total debt	[3]	177			177
Acquisition Corp. | 5.00% Senior Secured Notes
Debt Instrument [Line Items]
Total debt		300
Acquisition Corp. | 6.75% Senior Notes due 2022
Debt Instrument [Line Items]
Total debt		$ 635	$ 660		660
Holdings Company | 13.75% Senior Notes due 2019
Debt Instrument [Line Items]
Total debt				$ 150	$ 150

[1] Total long-term debt, including the current portion does not reflect the October 2016 tender offers for, and satisfaction and discharge of, the 6.000% Senior Secured Notes due 2021 and the 6.250% Senior Secured Notes due 2021, the October issuance of 4.125% Senior Secured Notes due 2024 and 4.875% Senior Secured Notes due 2024, the November 2016 Senior Term Loan Credit Agreement Amendment, or the November redemption of the 5.625% Senior Secured Notes due 2022. See “Recent Developments – Tender Offers and Satisfaction and Discharge” and “Liquidity – New Senior Secured Notes.”

[2] Principal amount of $978 million and $1.287 billion less unamortized discount of $3 million and $5 million at September 30, 2016 and September 30, 2015, respectively. Of this amount, $13 million, representing the scheduled amortization of the Term Loan, was included in the current portion of long term debt at September 30, 2015. The maturity date was extended to November 1, 2023, subject, in certain circumstances, to a springing maturity inside the maturity of certain of Acquisition Corp.’s other indebtedness.

[3] Face amount of €158 million. Above amounts represent the dollar equivalent of such notes at September 30, 2016 and September 30, 2015.