Earnings Per Share (Schedule Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net (loss) income	$ (33,623)	$ 67,106	$ 33,677	$ 211,576
Less: Preferred share dividends	(2,010)	(2,010)	(6,031)	(6,031)
Less: Loss (income) from operations attributable to noncontrolling interests	5,334	(1,641)	3,304	(5,065)
Less: Earnings allocated to unvested shares	(249)	(232)	(745)	(671)
Net (loss) income available for common shareholders, basic and diluted	$ (30,548)	$ 63,223	$ 30,205	$ 199,809
Weighted average common shares outstanding, basic and diluted	75,404	74,832	75,386	74,584
Net (loss) income available for common shareholders	$ (0.41)	$ 0.84	$ 0.40	$ 2.68