Segment Information - Long-Lived Assets and Revenue by Geographical Areas (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	10 Months Ended	12 Months Ended		3 Months Ended									12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	1 Months Ended	3 Months Ended						10 Months Ended	12 Months Ended	10 Months Ended	12 Months Ended	10 Months Ended	12 Months Ended	10 Months Ended	12 Months Ended
	Sep. 30, 2011	Jul. 19, 2011	Sep. 30, 2012	Sep. 30, 2010	Sep. 30, 2011 Successor [Member]	Sep. 30, 2012 Successor [Member]		Jun. 30, 2012 Successor [Member]		Mar. 31, 2012 Successor [Member]		Dec. 31, 2011 Successor [Member]		Sep. 30, 2012 Successor [Member]	Sep. 30, 2011 Successor [Member] United States [Member]	Sep. 30, 2012 Successor [Member] United States [Member]	Sep. 30, 2011 Successor [Member] United Kingdom [Member]	Sep. 30, 2012 Successor [Member] United Kingdom [Member]	Sep. 30, 2011 Successor [Member] All Other Territories [Member]	Sep. 30, 2012 Successor [Member] All Other Territories [Member]	Jul. 19, 2011 Predecessor [Member]	Jun. 30, 2011 Predecessor [Member]		Mar. 31, 2011 Predecessor [Member]		Dec. 31, 2010 Predecessor [Member]		Jul. 19, 2011 Predecessor [Member]	Sep. 30, 2010 Predecessor [Member]	Jul. 19, 2011 Predecessor [Member] United States [Member]	Sep. 30, 2010 Predecessor [Member] United States [Member]	Jul. 19, 2011 Predecessor [Member] United Kingdom [Member]	Sep. 30, 2010 Predecessor [Member] United Kingdom [Member]	Jul. 19, 2011 Predecessor [Member] All Other Territories [Member]	Sep. 30, 2010 Predecessor [Member] All Other Territories [Member]
Segment Reporting Information [Line Items]
Revenue	$ 556	$ 2,311	$ 2,780	$ 2,988	$ 556	$ 731	[1]	$ 651	[1]	$ 623	[1]	$ 775	[1]	$ 2,780	$ 215	$ 1,113	$ 78	$ 342	$ 263	$ 1,325	$ 162	$ 687	[1]	$ 684	[1]	$ 778	[1]	$ 2,311	$ 2,988	$ 936	$ 1,257	$ 293	$ 393	$ 1,082	$ 1,338
Long-lived Assets					$ 4,578	$ 4,339								$ 4,339	$ 3,154	$ 2,739	$ 252	$ 245	$ 1,172	$ 1,355

[1] The Company's business is seasonal. Therefore, quarterly operating results are not necessarily indicative of the results that may be expected for the full fiscal year.