Stock-Based Compensation (Schedule of Assumptions Used in Estimate of Fair Value of Stock Option Awards) (Details)	3 Months Ended			6 Months Ended		3 Months Ended	6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2012 Minimum [Member]	Mar. 31, 2013 Minimum [Member]	Mar. 31, 2012 Minimum [Member]	Mar. 31, 2012 Maximum [Member]	Mar. 31, 2013 Maximum [Member]	Mar. 31, 2012 Maximum [Member]
Expected term	5 years 9 months 20 days	5 years 10 months 24 days		5 years 9 months 20 days	5 years 10 months 24 days		8 years 7 months 8 days	8 years 6 months
Estimated volatility	54.90%		55.50%	48.70%	48.90%	55.60%	54.90%	55.60%
Estimated dividend yield	0.80%	0.70%		0.80%	0.70%		1.00%	1.10%
Risk-free interest rate	1.00%		1.00%	0.80%	1.00%	1.30%	1.30%	1.60%