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		6 Months Ended		3 Months Ended			6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Sep. 30, 2013 Subsequent Event [Member]	Jun. 30, 2013 Cumulative Series C Six Point Seven Five Percent Redeemable Perpetual Preferred Stock [Member]	Jun. 30, 2012 Cumulative Series C Six Point Seven Five Percent Redeemable Perpetual Preferred Stock [Member]	Jun. 30, 2013 Cumulative Series C Six Point Seven Five Percent Redeemable Perpetual Preferred Stock [Member]	Jun. 30, 2012 Cumulative Series C Six Point Seven Five Percent Redeemable Perpetual Preferred Stock [Member]	Jun. 30, 2013 Cumulative SeriesA Eight Point Zero Three Four Percent Redeemable Perpetual Preferred Stock [Member]	Jun. 30, 2012 Cumulative SeriesA Eight Point Zero Three Four Percent Redeemable Perpetual Preferred Stock [Member]	Jun. 30, 2013 Cumulative SeriesA Eight Point Zero Three Four Percent Redeemable Perpetual Preferred Stock [Member]	Jun. 30, 2012 Cumulative SeriesA Eight Point Zero Three Four Percent Redeemable Perpetual Preferred Stock [Member]	Jun. 30, 2013 Segment, Continuing Operations [Member]	Jun. 30, 2012 Segment, Continuing Operations [Member]	Jun. 30, 2013 Segment, Continuing Operations [Member]	Jun. 30, 2012 Segment, Continuing Operations [Member]
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, a two-for-one stock split of our common stock, effected by and in the form of a stock dividend, was paid to stockholders of record on July 5, 2013.
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	$ 18,621	$ 5,945	$ 55,062	$ 23,439
Net Income (Loss) Attributable to Noncontrolling Interest, Operating Partnerships	(1,597)	(197)	4,730	1,388										(1,337)	(166)	(4,196)	(1,368)
Redeemable Preferred Stock Dividends						2,329	0	(4,640)	0	0	4,038	0	(8,069)
Net Income (Loss) Available to Common Stockholders, Basic	17,860	2,063	52,883	14,495										14,955	1,741	46,226	14,002
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	2,905	322	6,657	493
Amounts allocated to dilutive securities	1,597	197	4,730	1,388										1,337	197	4,196	1,388
Net income (loss) available for Common Shares – fully diluted	$ 19,457	$ 2,260	$ 57,613	$ 15,883										$ 16,292	$ 1,938	$ 50,422	$ 15,390
Weighted average Common Shares outstanding - basic	83,021	82,262	83,024	82,220
Redemption of Common OP Units for Common Shares	7,456	7,913	7,456	7,936
Employee stock options and restricted shares	651	605	630	618
Weighted average Common Shares outstanding - fully diluted	91,128	90,780	91,110	90,774
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.18	$ 0.02	$ 0.55	$ 0.17
Income (Loss) from Discontinued Operations, Net of Tax, Per Basic Share	$ 0.04	$ 0.01	$ 0.09	$ 0.01
Net income (loss) available for Common Shares	$ 0.22	$ 0.03	$ 0.64	$ 0.18
Income (Loss) from Continuing Operations, Per Diluted Share	$ 0.18	$ 0.02	$ 0.55	$ 0.17
Income (Loss) from Discontinued Operations, Net of Tax, Per Diluted Share	$ 0.03	$ 0.00	$ 0.08	$ 0.00
Net income (loss) available for Common Shares	$ 0.21	$ 0.02	$ 0.63	$ 0.17
Stockholders' Equity Note, Stock Split, Conversion Ratio					2