Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Income tax provisions associated with income from continuing operations	$ 1,470,000	$ 1,466,000
Effective tax rates	28.90%	28.80%
U.S. federal statutory tax rate	35.00%	35.00%
Discrete tax benefit	200,000
Unrecognized tax benefits including interest and penalties	$ 1,000,000		$ 900,000