Calculation of Net Earnings (Loss) and Weighted Average Common Shares and Common Equivalent Shares Outstanding for Computation of Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net loss	$ (19,207)	$ (14,376)	$ (11,503)	$ (11,705)	$ (12,309)	$ (11,654)	$ (10,965)	$ (11,042)	$ (56,791)	$ (45,970)	$ (32,641)
Loss available to common shareholders									(56,791)	(45,970)	(32,641)
Loss attributable to common shareholders for diluted earnings per share									$ (56,791)	$ (45,970)	$ (32,641)
Weighted average number of common share equivalents:
Common shares used in basic loss per share									13,134,071	13,044,875	12,996,958
Total weighted average common shares and common share equivalents used in diluted loss per share									13,134,071	13,044,875	12,996,958
Loss per shares:
Basic	$ (1.46)	$ (1.09)	$ (0.88)	$ (0.89)	$ (0.94)	$ (0.89)	$ (0.84)	$ (0.85)	$ (4.32)	$ (3.52)	$ (2.51)
Diluted	$ (1.46)	$ (1.09)	$ (0.88)	$ (0.89)	$ (0.94)	$ (0.89)	$ (0.84)	$ (0.85)	$ (4.32)	$ (3.52)	$ (2.51)