Fair Value Measurements - Summary of Carrying Value and Estimated Fair Value of all Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Jun. 30, 2017
Carrying Value
Fair value measurement
Long term debt	$ 134,321	$ 164,571
Fair Value
Fair value measurement
Long term debt	162,623	174,676
Non-recurring basis | Carrying Value | Level 2 | 3.50% Convertible Notes
Fair value measurement
Long term debt		44,099
Non-recurring basis | Carrying Value | Level 2 | 3.50% Series A Convertible Notes
Fair value measurement
Long term debt		68,924
Non-recurring basis | Carrying Value | Level 2 | 3.75% Convertible Notes
Fair value measurement
Long term debt	68,598
Non-recurring basis | Fair Value | Level 2 | 3.50% Convertible Notes
Fair value measurement
Long term debt		48,146
Non-recurring basis | Fair Value | Level 2 | 3.50% Series A Convertible Notes
Fair value measurement
Long term debt		74,982
Non-recurring basis | Fair Value | Level 2 | 3.75% Convertible Notes
Fair value measurement
Long term debt	96,900
Revolving Credit Facility | Non-recurring basis | Carrying Value | Level 2
Fair value measurement
Long term debt	28,007	51,548
Revolving Credit Facility | Non-recurring basis | Fair Value | Level 2
Fair value measurement
Long term debt	28,007	$ 51,548
Term loan | Non-recurring basis | Carrying Value | Level 2
Fair value measurement
Long term debt	37,716
Term loan | Non-recurring basis | Fair Value | Level 2
Fair value measurement
Long term debt	$ 37,716