Employee Stock Purchase Plan (Details) - shares	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of shares covered under the Employee Stock Purchase Plan (ESPP)			250,000
Purchase price per share as percentage of fair market value	95.00%
Issuance of shares under employee stock purchase plan (in shares)	22,996	33,248
Shares available for future issuance under the ESPP	149,086