Earnings Per Share (Computation Of Basic Earnings And Diluted Earnings Per Share Data) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share [Abstract]
Net income	$ 9,047	$ 7,105	$ 17,540	$ 12,786
Weighted-average basic common shares outstanding	31,617,000	30,171,000	31,670,000	30,175,000
Stock options	2,673,000	2,598,000	2,609,000	2,557,000
Denominator for diluted earnings per share - Adjusted weighted-average shares	34,290,000	32,769,000	34,279,000	32,732,000
Basic	$ 0.29	$ 0.24	$ 0.55	$ 0.42
Diluted	$ 0.26	$ 0.22	$ 0.51	$ 0.39
Antidilutive securities excluded from computation of earnings per share, shares	890,000	470,000	920,000	451,000