Earnings Per Share (Basic And Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share [Abstract]
Net income	$ 25,632	$ 25,840	$ 39,971	$ 43,351
Weighted average common shares outstanding	72,091,000	73,022,000	72,382,000	73,140,000
Dilutive effect of stock-based awards	506,000	576,000	500,000	550,000
Shares used in computing diluted earnings per share	72,597,000	73,598,000	72,882,000	73,690,000
Basic earnings per share	$ 0.36	$ 0.35	$ 0.55	$ 0.59
Diluted earnings per share	$ 0.35	$ 0.35	$ 0.55	$ 0.59
Number of antidilutive options that were excluded from computation of earnings per share	0	0	0	0