Earnings per Common Share - Computation of Basic and Diluted Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share, Basic [Abstract]
Net income	$ 10,306	$ 5,436	$ 16,858	$ 10,120
Weighted average shares outstanding - basic (shares)	26,245	25,939	26,180	25,863
Basic EPS (US$ per share)	$ 0.39	$ 0.21	$ 0.64	$ 0.39
Earnings Per Share, Diluted [Abstract]
Dilutive stock options	168	59	157	65
Dilutive nonvested deferred shares	471	206	435	244
Diluted weighted average shares (shares)	26,884	26,204	26,772	26,172
Diluted EPS (US$ per share)	$ 0.38	$ 0.21	$ 0.63	$ 0.39