Earnings Per Share (Schedule Of Reconciliation Of Net Income/(Loss) to Net Income/(Loss) Available to Common Shareholders) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Net income/(loss)	$ 95,204	$ 60,940	$ 153,592	$ 113,153
Net income attributable to noncontrolling interest	2,852	2,852	5,672	5,703
Net income/(loss) attributable to controlling interest	92,352	58,088	147,920	107,450
Preferred stock dividends	1,550	1,550	3,100	3,100
Net income/(loss) available to common shareholders	$ 90,802	$ 56,538	$ 144,820	$ 104,350
Weighted average common shares outstanding - basic (shares)	233,482	231,573	233,280	233,112
Effect of dilutive securities	2,781	2,003	2,945	2,009
Weighted average common shares outstanding - diluted (shares)	236,263	233,576	236,225	235,121
Net income/(loss) per share available to common shareholders (in dollars per share)	$ 0.39	$ 0.24	$ 0.62	$ 0.45
Diluted income/(loss) per share available to common shareholders (in dollars per share)	$ 0.38	$ 0.24	$ 0.61	$ 0.44