Summary of Significant Accounting Policies and New Accounting Standards (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Net income	$ 14,748	$ 7,032	$ 31,062	$ 22,924
Weighted average number of shares - basic (in shares)	40,383	40,186	40,376	40,065
Dilutive effect of stock options and restricted stock units	140	178	147	264
Weighted average number of shares - diluted (in shares)	40,523	40,364	40,523	40,329
Net income per share
basic (in dollars per share)	$ 0.37	$ 0.17	$ 0.77	$ 0.57
diluted (in dollars per share)	0.36	0.17	0.77	0.57
Dividends per share (in dollars per share)	$ 0.12	$ 0.10	$ 0.22	$ 0.20