Earnings per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Earnings Per Share [Abstract]
Net earnings	$ 29,421	$ 21,169	$ 89,847	$ 74,390
Basic average shares outstanding	44,404,000	44,800,000	44,436,000	44,882,000
Dilutive effect of stock options and equivalents	675,000	496,000	585,000	259,000
Diluted average shares outstanding	45,079,000	45,296,000	45,021,000	45,141,000
Earnings per share
Basic earnings per share	$ 0.66	$ 0.47	$ 2.02	$ 1.66
Diluted earnings per share	$ 0.65	$ 0.47	$ 2.00	$ 1.65
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Options exercised to purchase common shares			816,570	44,700
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive options excluded from calculation of earnings per share, number of options	3,049,000	3,364,000	3,217,000	4,713,000
Antidilutive options excluded from calculation of earnings per share, weighted average exercise price	$ 46.46	$ 45.98	$ 46.05	$ 41.05