Valuation and Qualifying Accounts (Detail) (Allowance for Doubtful Accounts, USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2012
Allowance for Doubtful Accounts
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 7,928		$ 6,886		$ 9,530
Charged to Costs & Expenses	7,514		6,481		6,017
Other Changes Add (Deduct)	(6,222)	[1]	(5,439)	[1]	(8,661)	[1]
Balance at End of Year	$ 9,220		$ 7,928		$ 6,886

[1] Bad debts written off (net of recoveries).