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, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share Disclosure [Line Items]
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	$ 30,276	$ (6,632)	$ 104,206	$ 48,430
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	(2,219)	(2,753)	(7,929)	(7,483)
Net income (loss) available for Common Shares – basic	25,746	29,872	89,328	82,755
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	0	38,060	0	44,661
Amounts allocated to dilutive securities	2,219	2,753	7,929	7,483
Net income (loss) available for Common Shares – fully diluted	27,965	32,625	97,257	90,238
Weighted average Common Shares outstanding – basic	83,531	83,021	83,295	83,023
Employee stock options and restricted shares	743	634	705	620
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock	7,254	7,604	7,471	7,506
Weighted average Common Shares outstanding - fully diluted	91,528	91,259	91,471	91,149
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.31	$ (0.10)	$ 1.07	$ 0.46
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	$ 0.00	$ 0.46	$ 0.00	$ 0.54
Net income available for Common Shares	$ 0.31	$ 0.36	$ 1.07	$ 1.00
Income (Loss) from Continuing Operations, Per Diluted Share	$ 0.31	$ (0.10)	$ 1.06	$ 0.46
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	$ 0.00	$ 0.46	$ 0.00	$ 0.53
Net income available for Common Shares	$ 0.31	$ 0.36	$ 1.06	$ 0.99
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)	(2,311)	(6,949)	(6,951)
Segment, Continuing Operations [Member]
Earnings Per Share Disclosure [Line Items]
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable	(2,219)	755	(7,929)	(3,385)
Net income (loss) available for Common Shares – basic	25,746	(8,188)	89,328	38,094
Amounts allocated to dilutive securities	2,219	(755)	7,929	3,385
Net income (loss) available for Common Shares – fully diluted	$ 27,965	$ (8,943)	$ 97,257	$ 41,479