Stock-Based Compensation (Details 3) (Stock Option Plans, USD $)	6 Months Ended
	Mar. 31, 2013
Stock-Based Compensation
Outstanding Number of Shares	319,830
Exercisable Number of Shares	262,129
Exercise Price Per Share $12.80
Stock-Based Compensation
Exercise Price Per Share (in dollars per share)	$ 12.80
Remaining Contractual Life	1 year 5 months 1 day
Outstanding Number of Shares	32,207
Exercisable Number of Shares	32,207
Exercise Price Per Share $31.00
Stock-Based Compensation
Exercise Price Per Share (in dollars per share)	$ 31.00
Remaining Contractual Life	3 years
Outstanding Number of Shares	10,000
Exercisable Number of Shares	10,000
Exercise Price Per Share $72.93
Stock-Based Compensation
Exercise Price Per Share (in dollars per share)	$ 72.93
Remaining Contractual Life	4 years
Outstanding Number of Shares	59,500
Exercisable Number of Shares	59,500
Exercise Price Per Share $54.00
Stock-Based Compensation
Exercise Price Per Share (in dollars per share)	$ 54.00
Remaining Contractual Life	5 years
Outstanding Number of Shares	73,000
Exercisable Number of Shares	73,000
Exercise Price Per Share $46.83
Stock-Based Compensation
Exercise Price Per Share (in dollars per share)	$ 46.83
Remaining Contractual Life	5 years 6 months
Outstanding Number of Shares	20,000
Exercisable Number of Shares	20,000
Exercise Price Per Share $17.82
Stock-Based Compensation
Exercise Price Per Share (in dollars per share)	$ 17.82
Remaining Contractual Life	6 years
Outstanding Number of Shares	20,089
Exercisable Number of Shares	20,089
Exercise Price Per Share $34.00
Stock-Based Compensation
Exercise Price Per Share (in dollars per share)	$ 34.00
Remaining Contractual Life	6 years 9 months
Outstanding Number of Shares	25,801
Exercisable Number of Shares	25,801
Exercise Price Per Share $40.26
Stock-Based Compensation
Exercise Price Per Share (in dollars per share)	$ 40.26
Remaining Contractual Life	7 years 8 months 1 day
Outstanding Number of Shares	20,967
Exercisable Number of Shares	13,802
Exercise Price Per Share $55.88
Stock-Based Compensation
Exercise Price Per Share (in dollars per share)	$ 55.88
Remaining Contractual Life	8 years 8 months 1 day
Outstanding Number of Shares	20,866
Exercisable Number of Shares	7,730
Exercise Price Per Share $47.96
Stock-Based Compensation
Exercise Price Per Share (in dollars per share)	$ 47.96
Remaining Contractual Life	9 years 8 months 1 day
Outstanding Number of Shares	35,600
Exercise Price Per Share $48.39
Stock-Based Compensation
Exercise Price Per Share (in dollars per share)	$ 48.39
Remaining Contractual Life	9 years 8 months 1 day
Outstanding Number of Shares	1,800