Convertible 4.5% Senior Notes (Details)	1 Months Ended	12 Months Ended
	Jun. 30, 2016 USD ($) item $ / shares	Jun. 30, 2016 USD ($) $ / shares
Convertible debt
Interest rate (as a percent)	4.50%	4.50%
Proceeds from issuance of debt		$ 96,608,000
Issuance of debt transaction costs		$ 3,392,000
Convertible Notes
Convertible debt
Interest rate (as a percent)	4.50%	4.50%
Principal amount of debt	$ 100,000,000	$ 100,000,000
Proceeds from issuance of debt	96,600,000
Issuance of debt transaction costs	3,400,000
Interest expense		138,000
Principal amount of debt for conversion calculations	$ 1,000	$ 1,000
Ratio issued upon conversion	238.7775
Initial conversion price (in dollars per share) | $ / shares	$ 4.19	$ 4.19
Principal amount of notes to be repurchased under certain conditions (as a percent)	100
Principal amount of notes to be repurchased upon default (as a percent)	100
Additional interest for reporting requirement failure (as a percent)	0.5
Default cure period	90 days
Additional interest for restricted event (as a percent)	0.5
Number of additional interest rate percentage penalty circumstances | item	2
Maximum additional interest rate (as a percent)	0.5