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, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net income	$ 43,318	$ 38,264	$ 79,404	$ 66,071
Weighted average common shares outstanding	69,593	72,144	69,932	72,289
Dilutive effect of stock-based awards	300	232	297	233
Shares used in computing diluted earnings per share	69,893	72,376	70,229	72,522
Basic earnings per share	$ 0.62	$ 0.53	$ 1.14	$ 0.91
Diluted earnings per share	$ 0.62	$ 0.53	$ 1.13	$ 0.91
Number of antidilutive options that were excluded from computation of earnings per share	0	0	0	0