Earnings Per Share (Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Net income	$ 25,970	$ 21,259	$ 65,941	$ 64,610
Weighted average common shares outstanding	71,837,000	72,621,000	72,198,000	72,965,000
Dilutive effect of stock-based awards	527,000	595,000	508,000	565,000
Shares used in computing diluted earnings per share	72,364,000	73,216,000	72,706,000	73,530,000
Basic earnings per share	$ 0.36	$ 0.29	$ 0.91	$ 0.89
Diluted earnings per share	$ 0.36	$ 0.29	$ 0.91	$ 0.88
Number of antidilutive options that were excluded from computation of earnings per share	0	0	0	0