Comprehensive Income and Accumulated Other Comprehensive (Loss) Income (Details) (USD $)	3 Months Ended		9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Sep. 30, 2012
Comprehensive Income and Accumulated Other Comprehensive (Loss) Income
Foreign currency translation adjustments	$ (4,157,000)	$ (10,778,000)	$ (13,292,000)	$ (1,683,000)
Income tax benefit from foreign currency translation adjustments		200,000		200,000
Deferred gain on interest rate swaps		1,679,000		6,450,000
Income tax expense on interest rate swaps		700,000		2,500,000
Cumulative foreign currency translation adjustments, net of income taxes	23,900,000		23,900,000		10,700,000
Cumulative foreign translation adjustments, income tax expense (benefit)	$ 2,900,000		$ 2,900,000		$ 2,900,000