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, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Net income	$ 72,032	$ 39,132	$ 118,524	$ 62,190
Weighted average common shares outstanding	67,926	69,093	67,929	69,173
Dilutive effect of stock-based awards	290	342	308	358
Shares used in computing diluted earnings per share	68,216	69,435	68,237	69,531
Basic earnings per share	$ 1.06	$ 0.57	$ 1.74	$ 0.90
Diluted earnings per share	$ 1.06	$ 0.56	$ 1.74	$ 0.89