Net Loss Per Common Share - Additional Information (Details) - shares shares in Millions	9 Months Ended
	Mar. 31, 2018	Aug. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Feb. 28, 2013
3.50% Convertible Notes
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Interest rate (as a percent)	3.50%		3.50%	3.50%	3.50%
Date of convertible debt retired	2018-02
3.75% Convertible Senior Notes due 2022
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Interest rate (as a percent)	3.75%	3.75%	3.75%
Common stock not included in the calculation of potentially diluted shares	14.9