Stock Based Compensation (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended	12 Months Ended									12 Months Ended							12 Months Ended					0 Months Ended					0 Months Ended		12 Months Ended
	Jun. 30, 2014	Sep. 30, 2014	Sep. 30, 2014 Prior to October 1 2005	Sep. 30, 2014 After October 1 2005	Sep. 30, 2014 Minimum	Sep. 30, 2014 Maximum	Sep. 30, 2014 Restricted Stock Units (RSUs)	Sep. 30, 2013 Restricted Stock Units (RSUs)	Sep. 30, 2012 Restricted Stock Units (RSUs)	Sep. 30, 2011 Restricted Stock Units (RSUs)	Sep. 30, 2014 Restricted Stock Units (RSUs) Minimum	Sep. 30, 2014 Restricted Stock Units (RSUs) Maximum	Sep. 30, 2014 Employee Stock	Sep. 30, 2013 Employee Stock	Sep. 30, 2012 Employee Stock	Sep. 30, 2014 Stock Appreciation Rights (SARs)	Sep. 30, 2013 Stock Appreciation Rights (SARs)	Sep. 30, 2014 Stock Appreciation Rights (SARs) Minimum	Sep. 30, 2014 Stock Appreciation Rights (SARs) Maximum	Sep. 30, 2014 Options and Restricted Stock Units (RSUs)	Sep. 30, 2013 Options and Restricted Stock Units (RSUs)	Sep. 30, 2012 Options and Restricted Stock Units (RSUs)	Feb. 08, 2013 2007 Incentive Compensation Plan	Jul. 20, 2011 2007 Incentive Compensation Plan	Jul. 30, 2007 2007 Incentive Compensation Plan	Jul. 30, 2007 2007 Incentive Compensation Plan	Jul. 20, 2011 2007 Incentive Compensation Plan Restricted Stock Units (RSUs)	Sep. 17, 2012 2012 Inducement Option Plan Chingis	Sep. 17, 2012 2012 Inducement Option Plan Chingis	Sep. 30, 2014 1998 Stock Plan and 1996 Nonstatutory Stock Plan	Sep. 30, 2014 1998 Stock Plan and 1996 Nonstatutory Stock Plan Prior to October 1 2005	Sep. 30, 2014 1998 Stock Plan and 1996 Nonstatutory Stock Plan After October 1 2005	Sep. 30, 2014 1998 Stock Plan and 1996 Nonstatutory Stock Plan Minimum	Sep. 30, 2014 1998 Stock Plan and 1996 Nonstatutory Stock Plan Maximum	Sep. 30, 2014 1995 Employee Stock Purchase Plan	Sep. 30, 2013 1995 Employee Stock Purchase Plan	Sep. 30, 2012 1995 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares subject to options and awards outstanding (shares)		4,502,000					262,000	269,000	323,000	382,000						747,000	0
Shares available for future grant under the 2007 Plan (shares)		1,803,000
Option vesting term		4 years									2 years	4 years				4 years												6 months		4 years
Option cliff vesting period					6 months	1 year												6 months	1 year														6 months	1 year
Options expiration period for grants			10 years	7 years												7 years												7 years			10 years	7 years
Shares available for future issuance																										3,000,000	263,100
Additional shares available for issuance																							2,000,000	2,000,000	4,000,000
Granted (shares)																												439,500
Options exercise price (in dollars per share)																													$ 10.42
Vesting percentage																												12.50%
Portion vested of total shares																												0.0208
Offering period under stock purchase plan																																			6 months
Percentage discount from fair market value for shares purchased under the Employee Stock Purchase Plan																																			85.00%
Number of new options issued (in shares)																																			249,000	237,000	181,000
Common shares reserved for future issuance																																			332,000
Total unrecognized stock-based compensation expense		$ 8.1											$ 0.2			$ 2.9
Nonvested awards, total compensation cost not yet recognized, period for recognition		2 years 29 days											4 months			3 years 1 month 6 days
Total intrinsic value of options exercised and RSU's vested																				$ 10.4	$ 7.0	$ 5.7
Dividend yield	0.00%												0.75%	0.00%	0.00%
Weighted average grant date fair value (in dollars per share)							$ 11.62	$ 9.14	$ 9.42