Earnings Per Share (Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net income	$ 39,132	$ 43,318	$ 62,190	$ 79,404
Weighted average common shares outstanding	69,093	69,593	69,173	69,932
Dilutive effect of stock-based awards	342	300	358	297
Shares used in computing diluted earnings per share	69,435	69,893	69,531	70,229
Basic earnings per share	$ 0.57	$ 0.62	$ 0.90	$ 1.14
Diluted earnings per share	$ 0.56	$ 0.62	$ 0.89	$ 1.13
Number of antidilutive options that were excluded from computation of earnings per share	0	0	0	0