Earnings Per Share (Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net income	$ 46,332	$ 39,044	$ 108,522	$ 118,448
Weighted average common shares outstanding	69,097	69,198	69,148	69,684
Dilutive effect of stock-based awards	352	402	352	369
Shares used in computing diluted earnings per share	69,449	69,600	69,500	70,053
Basic earnings per share	$ 0.67	$ 0.56	$ 1.57	$ 1.70
Diluted earnings per share	$ 0.67	$ 0.56	$ 1.56	$ 1.69
Number of antidilutive options that were excluded from computation of earnings per share	0	0	0	0