Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Numerator: Net income	$ 18,298	$ 16,357	$ 37,735	$ 33,999
Weighted-average shares outstanding, basic (in shares)	28,293,000	27,713,000	28,164,000	27,665,000
Dilutive effect of share-based payments	304,000	245,000	270,000	263,000
Weighted-average shares outstanding, diluted (in shares)	28,597,000	27,958,000	28,434,000	27,928,000
Net income per common share, basic (in dollars per share)	$ 0.65	$ 0.59	$ 1.34	$ 1.23
Net income per common share, diluted (in dollars per share)	$ 0.64	$ 0.59	$ 1.33	$ 1.22
Weighted average shares excluded from the computation of diluted earnings per share	182,299	1,159,357	438,760	1,112,076