Financing Arrangements - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Mar. 19, 2012
Tranche A and Tranche A-1 Term Loan [Member]
Debt Instrument [Line Items]
Principal available	$ 25	$ 25
Loans outstanding	0	0
Tranche B Term Loan [Member]
Debt Instrument [Line Items]
Principal available	100	100
Loans outstanding	$ 0	$ 0