Earnings Per Share (Computation Of Basic And Diluted Earnings Per Share ) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Income from continuing operations		$ 17,179	$ 40,093	$ 81,164	$ 133,643
Loss from discontinued operations, net of tax			(190)		(2,757)
Net income		$ 17,179	$ 39,903	$ 81,164	$ 130,886
Average shares used in basic computation		69,633	66,691	68,675	66,344
Dilutive effect of stock options and units	[1]	10,126	9,990	9,651	9,667
Average shares used in diluted computation		79,759	76,681	78,326	76,011
Income from continuing operations		$ 0.25	$ 0.60	$ 1.18	$ 2.01
Loss from discontinued operations					(0.04)
Earnings per basic common share		0.25	0.60	1.18	1.97
Income from continuing operations		0.22	0.52	1.04	1.76
Loss from discontinued operations					(0.04)
Earnings per diluted common share		$ 0.22	$ 0.52	$ 1.04	$ 1.72

[1] Diluted earnings per share is computed on the basis of the weighted-average number of shares of common stock plus the effect of dilutive potential common shares outstanding during the period using the treasury stock method. Diluted earnings per share include stock options and units.