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	$ 4,055,000	$ 5,388,000	$ 7,992,000
Effective tax rate	236.60%	36.80%	367.50%	35.90%
Deferred tax assets	9,000,000		9,000,000
Release of a FIN 48 reserve related to the federal research and development tax credit	4,100,000		4,100,000
Operating loss carryforwards	32,000,000		32,000,000
Operating loss carryforwards, expiration period (in years)			20 years
Operating loss carryforwards, expiration date			2031
Operating loss carryforwards, valuation allowance	$ 9,000,000		$ 9,000,000
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