Earnings Per Common Share Calculation of numerator and denominator in eps table (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share Disclosure [Line Items]
Stockholders' Equity Note, Stock Split	On June 25, 2013, management announced a two-for-one split, to be effected by and in the form of a stock dividend, to take effect on July 15, 2013. On July 15, 2013, each common shareholder of record on July 5, 2013, received one additional share of common stock for each share held. On July 15, 2013, we effected a two-for-one stock split of our common stock, by and in the form of a stock dividend and was paid to stockholders of record on July 5, 2013.
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	$ (6,632)	$ 18,785	$ 48,430	$ 42,218
Net Income (Loss) Attributable to Noncontrolling Interest, Operating Partnerships	(2,753)	(1,503)	7,483	2,891
Redeemable Preferred Stock Dividends		(3,980)		12,048
Net Income (Loss) Available to Common Stockholders, Basic	29,872	16,009	82,755	30,504
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	38,060	2,475	44,661	2,948
Amounts allocated to dilutive securities	2,753	1,503	7,483	2,891
Net income (loss) available for Common Shares – fully diluted	32,625	17,512	90,238	33,395
Weighted average Common Shares outstanding – basic	83,021	82,380	83,023	82,274
Redemption of Common OP Units for Common Shares	7,604	7,884	7,506	7,918
Employee stock options and restricted shares	634	630	620	644
Weighted average Common Shares outstanding - fully diluted	91,259	90,894	91,149	90,836
Income from continuing operations	$ (0.10)	$ 0.16	$ 0.46	$ 0.33
Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share	$ 0.46	$ 0.03	$ 0.54	$ 0.04
Earnings Per Share, Basic	$ 0.36	$ 0.19	$ 1.00	$ 0.37
Income (Loss) from Continuing Operations, Per Diluted Share	$ (0.10)	$ 0.16	$ 0.46	$ 0.33
Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share	$ 0.46	$ 0.03	$ 0.53	$ 0.04
Earnings Per Share, Diluted	$ 0.36	$ 0.19	$ 0.99	$ 0.37
Stockholders' Equity Note, Stock Split, Conversion Ratio	2
Cumulative Series C Six Point Seven Five Percent Redeemable Perpetual Preferred Stock [Member]
Earnings Per Share Disclosure [Line Items]
Redeemable Preferred Stock Dividends	(2,311)	(587)	6,951	587
Cumulative SeriesA Eight Point Zero Three Four Percent Redeemable Perpetual Preferred Stock [Member]
Earnings Per Share Disclosure [Line Items]
Redeemable Preferred Stock Dividends	0	(3,393)	0	11,462
Segment, Continuing Operations [Member]
Earnings Per Share Disclosure [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interest, Operating Partnerships	755	(1,271)	(3,385)	(2,614)
Net Income (Loss) Available to Common Stockholders, Basic	(8,188)	13,534	38,094	27,556
Amounts allocated to dilutive securities	(755)	1,271	3,385	2,614
Net income (loss) available for Common Shares – fully diluted	$ (8,943)	$ 14,805	$ 41,479	$ 30,170