Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share [Abstract]
Net earnings	$ 42,579	$ 25,256	$ 39,591	$ 29,365	$ 40,445	$ 18,486	$ 30,569	$ 24,041	$ 136,791	$ 113,541	$ 123,650
Basic average shares outstanding									44,522	44,636	44,455
Dilutive effect of stock options and equivalents									801	774	630
Diluted average shares outstanding									45,323	45,410	45,085
Earnings per share
Basic earnings per share	$ 0.95	$ 0.57	$ 0.89	$ 0.66	$ 0.91	$ 0.41	$ 0.68	$ 0.54	$ 3.07	$ 2.54	$ 2.78
Diluted earnings per share	$ 0.94	$ 0.56	$ 0.87	$ 0.65	$ 0.89	$ 0.41	$ 0.67	$ 0.53	$ 3.02	$ 2.50	$ 2.74
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities, shares									900	1,800	3,100
Antidilutive securities, weighted average exercise price									$ 50.52	$ 50.54	$ 46.56