Earnings Per Share 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, Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 60,539	$ 50,712	$ 53,882	$ 46,088	$ 52,529	$ 42,606	$ 48,360	$ 43,220	$ 211,221	$ 186,715	$ 167,610
Common share information:
Weighted average shares outstanding for basic earnings per share	80,904	80,880	81,432	82,195	83,740	84,981	85,450	85,294	81,353	84,866	86,040
Dilutive effect of stock options and restricted stock									248	530	579
Weighted average shares outstanding for diluted earnings per share	81,086	81,094	81,634	82,589	84,276	85,467	85,986	85,854	81,601	85,396	86,619
Basic earnings per share	$ 0.75	$ 0.63	$ 0.66	$ 0.56	$ 0.63	$ 0.50	$ 0.57	$ 0.51	$ 2.60	$ 2.20	$ 1.95
Diluted earnings per share	$ 0.75	$ 0.63	$ 0.66	$ 0.56	$ 0.62	$ 0.50	$ 0.56	$ 0.50	$ 2.59	$ 2.19	$ 1.94
Antidilutive stock options and restricted stock excluded from computation of earnings per share									0	24	0