Subsequent Events - Additional Information (Detail) € in Millions						3 Months Ended			12 Months Ended
	Dec. 02, 2016 USD ($)	Nov. 21, 2016 USD ($)	Oct. 18, 2016 USD ($)	Oct. 07, 2016 USD ($)	Jul. 27, 2016 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2014 USD ($)	Nov. 30, 2016	Oct. 31, 2016	Oct. 18, 2016 EUR (€)	Sep. 30, 2015
Subsequent Event [Line Items]
Loss on extinguishment of debt							$ (14,000,000)	$ (4,000,000)	$ (18,000,000)	$ (141,000,000)
October 2016 Refinancing Transactions | Scenario, Forecast
Subsequent Event [Line Items]
Loss on extinguishment of debt						$ (31,000,000)
5.625% Senior Secured Notes
Subsequent Event [Line Items]
Interest rate										5.625%				5.625%
Acquisition Corp.
Subsequent Event [Line Items]
Loss on extinguishment of debt					$ 4,000,000
Acquisition Corp. | November 2016 Senior Term Loan Credit Agreement Amendment
Subsequent Event [Line Items]
Principal amount outstanding							$ 27,500,000		$ 27,500,000
Acquisition Corp. | 5.625% Senior Secured Notes
Subsequent Event [Line Items]
Interest rate							5.625%		5.625%					5.625%
Subsequent Event
Subsequent Event [Line Items]
Special cash dividends payable, date to be paid	Jan. 03, 2017
Special cash dividends	$ 54,000,000
Special cash dividends payable, date of record	Dec. 30, 2016
Subsequent Event | 4.125% Senior Secured Notes Due 2024
Subsequent Event [Line Items]
Interest rate												4.125%
Subsequent Event | 4.875% Senior Secured Notes Due 2024
Subsequent Event [Line Items]
Interest rate												4.875%
Subsequent Event | 6.000% Senior Secured Notes due 2021
Subsequent Event [Line Items]
Interest rate			6.00%										6.00%
Date instrument maturity, year			2021
Subsequent Event | 6.250% Senior Secured Notes Due 2021
Subsequent Event [Line Items]
Interest rate			6.25%									6.25%	6.25%
Date instrument maturity, year			2021
Subsequent Event | 5.625% Senior Secured Notes
Subsequent Event [Line Items]
Interest rate											5.625%
Subsequent Event | Acquisition Corp. | 4.125% Senior Secured Notes Due 2024
Subsequent Event [Line Items]
Face or principal amount of debt instrument | €													€ 345
Interest rate			4.125%										4.125%
Date instrument maturity, year			2024
Subsequent Event | Acquisition Corp. | 4.875% Senior Secured Notes Due 2024
Subsequent Event [Line Items]
Face or principal amount of debt instrument			$ 250,000,000
Interest rate			4.875%										4.875%
Date instrument maturity, year			2024
Subsequent Event | Acquisition Corp. | November 2016 Senior Term Loan Credit Agreement Amendment
Subsequent Event [Line Items]
Credit Facility maturity date		Nov. 01, 2023
Principal amount outstanding		$ 1,006,000,000
Subsequent Event | Acquisition Corp. | 5.625% Senior Secured Notes
Subsequent Event [Line Items]
Interest rate		5.625%
Date instrument maturity, year		2022
Principal amount outstanding		$ 247,500,000
Senior notes redeemed percent		10.00%
Redemption of senior notes		$ 27,500,000
Senior notes redemption price percent		103.00%
Subsequent Event | California | Headquarters Lease
Subsequent Event [Line Items]
Operating lease, agreement description				As of October 7, 2016, we entered into a lease agreement for new office space located in the Ford Factory Building at 777 S. Santa Fe Avenue, Los Angeles, California, 90021, to be used as our new Los Angeles, California headquarters beginning on August 1, 2017 for an initial term of 12 years and 9 months with a single option to extend the term of the lease for 10 years.
Operating lease, initial lease term				12 years 9 months
Operating lease, option to extend lease term				10 years
Operating lease, rental payments subject to annual fixed increases				$ 10,000,000
Operating lease, rent abatement percentage				75.00%
Operating lease, rent abatement period				16 months