Earnings Per Share Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 50,609	$ 46,757	$ 53,982	$ 49,788	$ 47,669	$ 45,996	$ 40,505	$ 42,475	$ 201,136	$ 176,645	$ 154,984
Common share information:
Weighted average shares outstanding for basic earnings per share	83,740	84,981	85,450	85,294	85,845	86,120	86,084	86,109	84,866	86,040	86,599
Dilutive effect of stock options and restricted stock									530	579	688
Weighted average shares outstanding for diluted earnings per share	84,276	85,467	85,986	85,854	86,525	86,705	86,639	86,605	85,396	86,619	87,287
Basic earnings per share	$ 0.60	$ 0.55	$ 0.63	$ 0.58	$ 0.56	$ 0.53	$ 0.47	$ 0.49	$ 2.37	$ 2.05	$ 1.79
Diluted earnings per share	$ 0.60	$ 0.55	$ 0.63	$ 0.58	$ 0.55	$ 0.53	$ 0.47	$ 0.49	$ 2.36	$ 2.04	$ 1.78
Antidilutive stock options and restricted stock excluded from computation of earnings per share									24	0	0