Convertible Senior Notes (Details)			1 Months Ended	3 Months Ended
	Sep. 21, 2017 USD ($) item shares	Sep. 21, 2017 USD ($) item	Feb. 28, 2015 USD ($) $ / shares shares	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)
Debt Instrument [Line Items]
Conversion of debt				$ 80,000,000
Loss on induced exchanges of debt				13,005,329
Amortization of debt issuance costs				$ 1,569,116	$ 182,454
4.75% Convertible Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Debt instrument, face amount			$ 100,000,000
Net proceeds from debt			96,300,000
Payment of debt issuance costs			$ 3,700,000
Debt instrument, stated percentage			4.75%	4.75%
Frequency of interest payments				semiannually
Debt instrument, effective interest rate				5.48%
Number of shares issuable under conversion of debt | shares			19,600,000
Debt conversion ratio		176.2502		195.8336
Principal amount of Convertible Senior Notes	$ 1,000		$ 1,000
Conversion price of debt | $ / shares			$ 5.11
Percentage of principal amount redeemable			100.00%
Conversion of debt	$ 80,000,000
Number of tranches | item	3	3
Shares issued in exchange | shares	16,799,861
Number of shares converted | shares	1,133,173
Loss on induced exchanges of debt	$ 13,000,000
Outstanding aggregate principal amount	$ 20,000,000	$ 20,000,000
Interest expense				$ 2,600,000	1,400,000
Amortization of debt issuance costs				1,600,000	$ 200,000
Accelerated amortization of debt issuance costs				$ 1,400,000