Subsequent Events - Schedule of Proforma Debt (Parenthetical) (Detail)			6 Months Ended		6 Months Ended		6 Months Ended			6 Months Ended						6 Months Ended
	Mar. 31, 2014 USD ($)	Sep. 30, 2013 USD ($)	Mar. 31, 2014 Term Loan Facility due 2020 USD ($)	Sep. 30, 2013 Term Loan Facility due 2020 USD ($)	Mar. 31, 2014 6.00% Senior Secured Notes	Mar. 31, 2013 6.00% Senior Secured Notes	Mar. 31, 2014 6.25% Senior Secured Notes EUR (€)	Sep. 30, 2013 6.25% Senior Secured Notes EUR (€)	Mar. 31, 2013 6.25% Senior Secured Notes	Mar. 31, 2014 13.75% Holdings Notes due 2019	Mar. 31, 2014 Revolving Credit Facility USD ($)		Sep. 30, 2013 Revolving Credit Facility USD ($)		Mar. 31, 2014 Pro Forma USD ($)	Mar. 31, 2014 Pro Forma Term Loan Facility due 2020 USD ($)	Mar. 31, 2014 Pro Forma 6.00% Senior Secured Notes	Mar. 31, 2014 Pro Forma 6.25% Senior Secured Notes EUR (€)	Mar. 31, 2014 Pro Forma 6.75% Senior Notes due 2022	Mar. 31, 2014 Pro Forma New Senior Secured Notes	Mar. 31, 2014 Pro Forma 11.5% Senior Notes due 2018	Mar. 31, 2014 Pro Forma 13.75% Holdings Notes due 2019	Mar. 31, 2014 Pro Forma Revolving Credit Facility USD ($)
Proforma Debt Instrument [Line Items]
Maturity date			2020		2021		2021			2019						2020	2021	2021	2022	2022	2018	2019
Interest rate					6.00%	6.00%	6.25%		6.25%	13.75%							6.00%	6.25%	6.75%	5.625%	11.50%	13.75%
Commitments under revolving credit facility											$ 150,000,000												$ 150,000,000
Letters of credit outstanding											11,000,000		1,000,000										11,000,000
Revolving Credit Facility Outstanding											0		0										0
Face or Principal amount of Debt Instrument			1,307,000,000	1,310,000,000			158,000,000	158,000,000								1,307,000,000		158,000,000
Unamortized discount			7,000,000	7,000,000												7,000,000
Current portion of long-term debt	$ 13,000,000	$ 13,000,000	$ 13,000,000	$ 13,000,000								[1]		[1]	$ 13,000,000	$ 13,000,000								[2]

[1] Reflects $150 million of commitments under the Revolving Credit Facility, less letters of credit outstanding of approximately $11 million and $1 million at March 31, 2014 and September 30, 2013, respectively. There were no loans outstanding under the Revolving Credit Facility at March 31, 2014 or September 30, 2013.

[2] Reflects $150 million of commitments under the Revolving Credit Facility, less letters of credit outstanding of approximately $11 million at March 31, 2014. There were no loans outstanding under the Revolving Credit Facility at March 31, 2014.