Earnings Per Share (Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Income from continuing operations	$ 32,042	$ 40,440
Loss from discontinued operations, net of taxes	(362)	(110)
Net income	31,680	40,330
Weighted average shares and assumed conversions	100,086,000	109,543,000
Income from continuing operations, Basic	$ 0.32	$ 0.37
Loss from discontinued operations, net of taxes, Basic
Net income	$ 0.32	$ 0.37
Income from continuing operations, Diluted	$ 0.32	$ 0.37
Loss from discontinued operations, net of taxes, Diluted
Net income	$ 0.32	$ 0.37
Anti-dilutive stock options excluded from computations of diluted earnings per share	1,500,000	1,300,000
Stock Options [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive securities	631,000	693,000
Restricted Stock-Based Compensation [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive securities	163,000	162,000
Basic [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Income from continuing operations	32,042	40,440
Loss from discontinued operations, net of taxes	(362)	(110)
Net income	31,680	40,330
Weighted average common shares outstanding, basic	99,292,000	108,688,000
Diluted [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Income from continuing operations	32,042	40,440
Loss from discontinued operations, net of taxes	(362)	(110)
Net income	$ 31,680	$ 40,330
Weighted average common shares outstanding, diluted	99,292,000	108,688,000