Net Income Per Common Share (Schedule 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
Basic Earnings (Loss) Per Share
Net income available to common shareholders	$ 55,369	$ 44,229	$ 160,006	$ 134,399
Weighted average common shares outstanding	131,516	139,043	133,120	138,989
Net income per common share, basic	$ 0.42	$ 0.32	$ 1.20	$ 0.97
Diluted Earnings (Loss) Per Share
Net income available to common shareholders	$ 55,369	$ 44,229	$ 160,006	$ 134,399
Weighted average common shares outstanding	131,516	139,043	133,120	138,989
Potentially dilutive shares from assumed exercise of securities or other contracts to purchase common stock	781	683	756	611
Weighted average number of diluted common shares	132,297	139,726	133,876	139,600
Net income per common share, diluted	$ 0.42	$ 0.32	$ 1.20	$ 0.96