Earnings Per Common Share (Schedule Of Basic And Diluted Earnings Per Common Share) (Details) (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Earnings Per Common Share [Abstract]
Net income	$ 41,003	$ 23,673	$ 118,236	$ 93,869
Series A and B preferred share dividends	(5,105)	(5,058)	(15,223)	(15,175)
Unvested stock award participation in earnings	(148)	(104)	(434)	(437)
Numerator for basic earnings per common share	35,750	18,511	102,579	78,257
Weighted average common shares outstanding	84,147	70,129	77,852	69,879
Average unvested stock awards outstanding	(465)	(393)	(461)	(389)
Denominator for basic earnings per common share	83,682	69,736	77,391	69,490
Basic earnings per common share	$ 0.43	$ 0.27	$ 1.33	$ 1.13
Dividends on antidilutive convertible preferred shares	(5,031)	(4,983)	(14,999)	(14,949)
Numerator for diluted earnings per common share	$ 35,824	$ 18,586	$ 102,803	$ 78,483
Net effect of dilutive stock and option awards	77	34	74	39
Net effect of dilutive convertible preferred shares	309	310	309	310
Denominator for diluted earnings per common share	84,068	70,080	77,774	69,839
Diluted earnings per common share	$ 0.43	$ 0.27	$ 1.32	$ 1.12