Components of Interest Expense, Net (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Interest Income Expense Net [Line Items]
Interest expense	$ (14,474)	$ (14,110)	$ (15,710)
Interest income	41	50	56
Interest expense, net	$ (14,433)	$ (14,060)	$ (15,654)