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		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net income/(loss)	$ 71,769	$ 67,635	$ 225,361	$ 180,788
Net income attributable to noncontrolling interest	2,883	2,883	8,555	8,586
Net income/(loss) attributable to controlling interest	68,886	64,752	216,806	172,202
Preferred stock dividends	1,550	1,550	4,650	4,650
Net income/(loss) available to common shareholders	$ 67,336	$ 63,202	$ 212,156	$ 167,552
Weighted average common shares outstanding - basic (shares)	233,749	231,856	233,438	232,690
Effect of dilutive securities (shares)	2,591	2,236	2,934	2,085
Weighted average common shares outstanding - diluted (shares)	236,340	234,092	236,372	234,775
Net income/(loss) per share available to common shareholders (in dollars per share)	$ 0.29	$ 0.27	$ 0.91	$ 0.72
Diluted income/(loss) per share available to common shareholders (in dollars per share)	$ 0.28	$ 0.27	$ 0.90	$ 0.71