Series A Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands		6 Months Ended
	May 03, 2017	Sep. 30, 2019	Sep. 30, 2018
Series A Convertible Preferred Stock
Cash dividends paid		$ 2,092	$ 2,092
Series A Convertible Preferred Stock
Series A Convertible Preferred Stock
Direct and incremental expenses incurred	$ 1,154
Declared and accrued dividends		686	686
Cash dividends paid		$ 2,092	$ 2,092
Series A Convertible Preferred Stock | After May 3, 2024
Series A Convertible Preferred Stock
Increase in preference dividend rate, per annum upon failure to repurchase (as a percent)		1.00%
Additional increase in preference dividend rate, per annum on each anniversary of the date that the Company is required to effect such repurchase (as a percent)		1.00%
Series A Convertible Preferred Stock | After May 3, 2024 | Maximum
Series A Convertible Preferred Stock
Dividend rate (as a percent)		6.875%
Series A Convertible Preferred Stock | Orogen
Series A Convertible Preferred Stock
Sale of convertible preferred stock (in shares)	108,000
Shares issuable upon conversion (in shares)	3,000,000
Aggregate purchase price	$ 108,000
Conversion price (in dollars per share)	$ 36.00
Dividend rate (as a percent)	3.875%