Stock-based Compensation (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant under the 2007 Plan (shares)	1,910,000
Option vesting period (years)	4 years
Percentage discount from fair market value for shares purchased under the Employee Stock Purchase Plan	85.00%
Offering period (years)	6 months
Shares available for future issuance under the Employee Stock Purchase Plan (shares)	581,000
Prior to October 1 2005
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option expiration period (years)	10 years
After October 1 2005
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option expiration period (years)	7 years
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option Cliff vesting period	6 months
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option Cliff vesting period	1 year
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average fair value of grants	$ 10.96	$ 9.14
Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU vesting period (years)	2 years
Restricted Stock Units (RSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU vesting period (years)	4 years
SARS
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period (years)	4 years
Option expiration period (years)	7 years
Total unrecognized stock-based compensation expense	$ 4,000
Nonvested awards, total compensation cost not yet recognized, period for recognition (years)	3 years 10 months 6 days
SARS | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option Cliff vesting period	6 months
SARS | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option Cliff vesting period	1 year
Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized stock-based compensation expense	10,700
Nonvested awards, total compensation cost not yet recognized, period for recognition (years)	2 years 9 months 17 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized stock-based compensation expense	$ 53
Nonvested awards, total compensation cost not yet recognized, period for recognition (years)	1 month