Stock-Based Compensation (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended		3 Months Ended		6 Months Ended
	Dec. 10, 2012	Nov. 20, 2012	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 item	Mar. 31, 2012
Original option plan August 2004
Information relating to stock options
Number of shares of common stock reserved for issuance			1,000,000		1,000,000
Second option plan January 2007
Information relating to stock options
Number of shares of common stock reserved for issuance			500,000		500,000
Stock Option Plans
Information relating to stock options
Number of plans					2
Number of shares of common stock reserved for issuance			1,500,000		1,500,000
Period during which options are exercisable					10 years
Vesting of awards per year (as a percent)					33.33%
Award vesting period					3 years
Fair value assumptions
Fair Value (in dollars per share)	$ 14.12	$ 13.92
Dividend Yield (as a percent)	1.82%	1.83%
Risk-Free Interest Rate (as a percent)	0.33%	0.32%
Expected Volatility (as a percent)	47.00%	47.00%
Expected Life	3 years	3 years
Stock-based employee compensation expense			$ 107	$ 165	$ 209	$ 302
Remaining unrecognized compensation expense			737		737
Weighted average period for recognition					1 year 7 months 13 days
Activity under stock option plans, number of shares
Outstanding at beginning of the period (in shares)					318,776
Granted (in shares)					37,400
Exercised (in shares)					(30,545)
Canceled (in shares)					(5,801)
Outstanding at end of the period (in shares)			319,830		319,830
Vested or expected to vest (in shares)			311,263		311,263
Exercisable at end of period (in shares)			262,129,000		262,129,000
Outstanding at end of period, Aggregate Intrinsic Value			3,768		3,768
Vested or expected to vest, Aggregate Intrinsic Value			3,699		3,699
Exercisable at end of the period, Aggregate Intrinsic Value			$ 3,389		$ 3,389
Weighted Average Exercise Prices
Outstanding at beginning of the period (in dollars per share)					$ 44.05
Granted (in dollars per share)					$ 47.98
Exercised (in dollars per share)					$ 19.57
Canceled (in dollars per share)					$ 44.39
Outstanding at end of period (in dollars per share)			$ 46.84		$ 46.84
Vested or expected to vest (in dollars per share)			$ 43.88		$ 43.88
Exercisable at end of the period (in dollars per share)			$ 46.40		$ 46.40
Outstanding at end of the period, Weighted Average Remaining Contractual Life					5 years 7 months 2 days
Vested or expected to vest, Weighted Average Remaining Contractual Life					5 years 7 months 2 days
Exercisable at end of the period, Weighted Average Remaining Contractual Life					4 years 9 months 14 days
Stock Option Plans | Certain Employees
Activity under stock option plans, number of shares
Granted (in shares)	1,800	35,600
Weighted Average Exercise Prices
Granted (in dollars per share)	$ 48.39	$ 47.96