Income Per Share Data - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]
Weighted average diluted shares outstanding excluded outstanding stock options	200,000	300,000	400,000	500,000
Common stock repurchased, Shares			485,577
Common stock repurchased			$ 11.5