Income/(loss) per common share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Net income/(loss)	$ (2,804)	$ (8,428)	$ 14,625	$ (2,763)
Less: Income to participating securities			(125)
Net income/(loss) attributable to common shares	$ (2,804)	$ (8,428)	$ 14,500	$ (2,763)
Weighted average common shares outstanding - basic	43,554	43,072	43,431	42,863
Effect of dilutive stock equivalents (in shares)			319
Weighted average common shares outstanding - dilutive	43,554	43,072	43,750	42,863
Net income per common share - basic (in dollars per share)	$ (0.06)	$ (0.20)	$ 0.33	$ (0.06)
Net income per common share - diluted (in dollars per share)	$ (0.06)	$ (0.20)	$ 0.33	$ (0.06)