Valuation and Qualifying Accounts (Details) - Allowance for Doubtful Accounts - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Movement in Valuation Allowances and Reserves
Balance at beginning of year		$ 5,599	$ 6,992	$ 5,519
Charged to costs and expenses		7,760	13,498	13,149
Other	[1]	(9,413)	(14,891)	(11,676)
Balance at end of year		$ 3,946	$ 5,599	$ 6,992

[1] Uncollectible accounts written off, net of recoveries