Stock-Based Compensation (Tables)

6 Months Ended

Mar. 31, 2014

Stock-Based Compensation [Abstract]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

Fair value is estimated at the grant date based on a Black-Scholes-Merton option-pricing model using the following weighted-average assumptions:

	Six Months Ended March 31, 2014
Expected stock price volatility	34%
Expected dividend yield	—%
Risk free interest rate	0.80%
Average expected life (in years)	2.88

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

The following is a summary of stock option activity for the six months ended March 31, 2014:

	Shares Available for Grant		Number of Options Outstanding		Weighted Average Price		Weighted Average Grant Date Fair Value		Weighted Average Remaining Term (in years)	Aggregate Intrinsic Value ($ millions)
Balances as of September 30, 2013	1,000,000		1,779,983		$	24.76	$	11.44	4.87	$	4.8
Granted	(86,500	)	86,500		$	19.24	$	4.48
Exercised			(140,992	)	$	8.84	$	4.02
Forfeited	—		(80,000	)	$	25.91	$	13.63
Expired	—		(32,647	)	$	50.64	$	14.27
Balances as of March 31, 2014	913,500		1,612,844		$	24.27	$	11.55	4.60	$	2.4
Exercisable as of March 31, 2014			665,031		$	26.30	$	10.73	1.60	$	2.3

Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]

The following is a summary of restricted stock activity for the six months ended March 31, 2014:

	Shares Available for Grant		Number of Shares Outstanding		Weighted Average Grant Date Fair Value		Weighted Average Remaining Term (in years)	Aggregate Intrinsic Value ($ millions)
Balances as of September 30, 2013	1,154,862		363,638		$	20.53	1.74	$	7.4
Granted	(75,699	)	75,699		$	19.69
Vested			(134,646	)	$	20.20
Forfeited	30,845		(54,481	)	$	21.68
Balances as of March 31, 2014	1,110,008		250,210		$	20.20	2.11	$	4.7