Share-Based Compensation (Details)	12 Months Ended
	Sep. 30, 2011 Year	Sep. 30, 2010 Year	Sep. 30, 2009 Year
Black Scholes Pricing Model [Member]
Share-Based Compensation
Average risk-free interest rate	1.94%	2.15%	1.63%
Expected dividend yield	2.37%	3.16%	2.47%
Expected volatility	39.00%	41.00%	35.00%
Expected term (years)	5.5	5.5	5.4
Monte Carlo Simulation [Member]
Share-Based Compensation
Average risk-free interest rate	0.63%	1.22%	1.46%
Expected dividend yield	2.01%	2.51%	2.47%
Expected volatility	49.00%	48.00%	40.00%