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Income Taxes (Narrative) (Details) (USD $) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Mar. 31, 2015 | Mar. 31, 2014 | Mar. 31, 2015 | Mar. 31, 2014
Income Tax Contingency [Line Items] |  |  |  |
Income tax provision | $ 6,379,000 us-gaap_IncomeTaxExpenseBenefit | $ 4,055,000 us-gaap_IncomeTaxExpenseBenefit | $ 5,388,000 us-gaap_IncomeTaxExpenseBenefit | $ 7,992,000 us-gaap_IncomeTaxExpenseBenefit
Effective tax rate | 236.60%us-gaap_EffectiveIncomeTaxRateContinuingOperations | 36.80%us-gaap_EffectiveIncomeTaxRateContinuingOperations | 367.50%us-gaap_EffectiveIncomeTaxRateContinuingOperations | 35.90%us-gaap_EffectiveIncomeTaxRateContinuingOperations
Deferred tax assets | 9,000,000 us-gaap_DeferredTaxAssetsValuationAllowance |  | 9,000,000 us-gaap_DeferredTaxAssetsValuationAllowance |
Release of a FIN 48 reserve related to the federal research and development tax credit | 4,100,000 us-gaap_UnrecognizedTaxBenefits |  | 4,100,000 us-gaap_UnrecognizedTaxBenefits |
Operating loss carryforwards | 32,000,000 us-gaap_OperatingLossCarryforwards |  | 32,000,000 us-gaap_OperatingLossCarryforwards |
Operating loss carryforwards, expiration period (in years) |  |  | 20 years |
Operating loss carryforwards, expiration date |  |  | 2031 |
Operating loss carryforwards, valuation allowance | $ 9,000,000 us-gaap_OperatingLossCarryforwardsValuationAllowance |  | $ 9,000,000 us-gaap_OperatingLossCarryforwardsValuationAllowance |
R&D Tax Credit |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Tax credit carryforward description |  |  | The effective tax rate for the six months ended March 31, 2015 was 367.5% compared to an effective tax rate of 35.9% for the six months ended March 31, 2014 primarily due to a valuation allowance against our Canadian deferred tax assets partially offset by the release of a FIN 48 reserve related to the R&D Credit upon closing an IRS audit as well as the December 19, 2014 retroactive reinstatement of the R&D Credit from January 1, 2014 through December 31, 2014. |
Tax credit expiration date |  |  | Dec. 31, 2014 |

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- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319 + Details
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