Earnings per Common Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share, Basic [Abstract]
Net income (loss)	$ (5,153)	$ (13,821)	$ 3,203	$ 771
Weighted average shares outstanding - basic (shares)	26,817	26,594	26,747	26,511
Basic EPS (US$ per share)	$ (0.19)	$ (0.52)	$ 0.12	$ 0.03
Earnings Per Share, Diluted [Abstract]
Dilutive stock options	0	0	29	51
Dilutive nonvested deferred shares	0	0	278	276
Diluted weighted average shares (shares)	26,817	26,594	27,054	26,838
Diluted EPS (US$ per share)	$ (0.19)	$ (0.52)	$ 0.12	$ 0.03