Financial Instruments - Convertible Notes (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Jun. 30, 2015	Apr. 17, 2014	Feb. 28, 2013	Aug. 01, 2011
3.75% Convertible Notes
Fair value measurement
Interest rate (as a percent)	3.75%	3.75%			3.75%
3.50% Convertible Notes
Fair value measurement
Interest rate (as a percent)	3.50%	3.50%	3.50%	3.50%
3.50% Series A Convertible Notes
Fair value measurement
Interest rate (as a percent)	3.50%	3.50%	3.50%
Non-recurring basis | Carrying Value | Level 2
Fair value measurement
Long term debt	$ 210,412	$ 199,655
Non-recurring basis | Carrying Value | 3.75% Convertible Notes | Level 2
Fair value measurement
Long term debt	36,400	92,863
Non-recurring basis | Carrying Value | 3.50% Convertible Notes | Level 2
Fair value measurement
Long term debt	43,195	42,332
Non-recurring basis | Carrying Value | 3.50% Series A Convertible Notes | Level 2
Fair value measurement
Long term debt	66,613	64,460
Non-recurring basis | Carrying Value | Secured Loan | Level 2
Fair value measurement
Long term debt	64,204
Non-recurring basis | Fair Value | Level 2
Fair value measurement
Long term debt	233,194	270,635
Non-recurring basis | Fair Value | 3.75% Convertible Notes | Level 2
Fair value measurement
Long term debt	36,487	102,645
Non-recurring basis | Fair Value | 3.50% Convertible Notes | Level 2
Fair value measurement
Long term debt	51,450	65,230
Non-recurring basis | Fair Value | 3.50% Series A Convertible Notes | Level 2
Fair value measurement
Long term debt	81,053	$ 102,760
Non-recurring basis | Fair Value | Secured Loan | Level 2
Fair value measurement
Long term debt	$ 64,204