Earnings per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Earnings Per Share [Abstract]
Numerator: Net income	$ 17,642	$ 18,380
Denominator: Weighted-average shares, basic	27,618,000	27,138,000
Denominator: Dilutive effect of share-based payments	283,000	413,000
Denominator: Weighted-average shares, diluted	27,901,000	27,551,000
Net income per common share, basic	$ 0.64	$ 0.68
Net income per common share, diluted	$ 0.63	$ 0.67
Weighted average shares excluded from the computation of diluted earnings per share	1,058,235	692,856