Consolidated Statements of Income and Comprehensive Income (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Revenues:
Community base rental income	$ 101,468,000	$ 98,336,000	$ 202,244,000	$ 196,433,000
Rental home income	3,598,000	2,786,000	6,992,000	5,367,000
Resort base rental income	33,197,000	30,408,000	73,936,000	67,987,000
Right-to-use annual payments	12,043,000	12,221,000	23,566,000	23,972,000
Right-to-use contracts current period, gross	3,361,000	2,942,000	6,192,000	5,186,000
Right-to-use contracts, deferred, net of prior period amortization	(1,550,000)	(1,285,000)	(2,590,000)	(1,891,000)
Utility and other income	15,787,000	17,097,000	32,470,000	33,053,000
Gross revenues from home sales	4,217,000	1,921,000	6,913,000	3,925,000
Brokered resale revenues and ancillary services revenues, net	932,000	482,000	2,727,000	2,225,000
Interest income	2,076,000	1,908,000	3,974,000	4,012,000
Income from other investments, net	1,624,000	1,567,000	4,104,000	3,055,000
Total revenues	176,753,000	168,383,000	360,528,000	343,324,000
Expenses:
Property operating and maintenance	58,345,000	56,882,000	113,401,000	109,850,000
Rental home operating and maintenance	1,487,000	1,281,000	3,357,000	2,694,000
Real estate taxes	11,888,000	11,510,000	24,290,000	23,367,000
Sales and marketing, gross	3,333,000	2,632,000	5,694,000	4,275,000
Sales and marketing, deferred commissions, net	(655,000)	(655,000)	(1,118,000)	(897,000)
Property management	10,170,000	9,312,000	20,303,000	18,947,000
Depreciation on real estate and rental homes	29,313,000	25,523,000	55,333,000	50,947,000
Amortization of Intangible Assets for Continuing Operations	159,000	15,650,000	318,000	31,265,000
Cost of home sales	3,919,000	2,514,000	6,700,000	4,681,000
Home selling expenses	454,000	399,000	981,000	728,000
General and administrative	6,946,000	6,810,000	13,655,000	12,909,000
Payments of Debt Extinguishment Costs	1,381,000	0	1,381,000	0
Rent control initiatives and other	1,624,000	367,000	1,856,000	846,000
Interest and related amortization	30,377,000	30,705,000	60,500,000	61,528,000
Total expenses	158,741,000	162,930,000	306,651,000	321,140,000
Income before equity in income of unconsolidated joint ventures	18,012,000	5,453,000	53,877,000	22,184,000
Equity income from unconsolidated joint ventures	609,000	492,000	1,185,000	1,255,000
Consolidated income from continuing operations	18,621,000	5,945,000	55,062,000	23,439,000
Net income from discontinued operations	3,165,000	353,000	6,233,000	513,000
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	0	0	958,000	0
Income allocated to non-controlling interest - discontinued operations	3,165,000	353,000	7,191,000	513,000
(Income) loss allocated to non-controlling interests - Common OP Units	(1,597,000)	(197,000)	4,730,000	1,388,000
Net income (loss) available for Common Shares – basic	17,860,000	2,063,000	52,883,000	14,495,000
Consolidated net income	21,786,000	6,298,000	62,253,000	23,952,000
Other comprehensive loss:
Adjustment for fair market value of swap	430,000	(34,000)	872,000	(412,000)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	22,216,000	6,264,000	63,125,000	23,540,000
Comprehensive income (loss) attributable to Common Shareholders	18,254,000	2,031,000	53,683,000	14,118,000
Earnings per Common Share - Basic:
Income from continuing operations	$ 0.18	$ 0.02	$ 0.55	$ 0.17
Income from discontinued operations	$ 0.04	$ 0.01	$ 0.09	$ 0.01
Net income (loss) available for Common Shares	$ 0.22	$ 0.03	$ 0.64	$ 0.18
Earnings per Common Share - Fully Diluted:
Income (Loss) from Continuing Operations, Per Diluted Share	$ 0.18	$ 0.02	$ 0.55	$ 0.17
Income from discontinued operations	$ 0.03	$ 0.00	$ 0.08	$ 0.00
Net income (loss) available for Common Shares	$ 0.21	$ 0.02	$ 0.63	$ 0.17
Distributions declared per Common Share outstanding	$ 0.25	$ 0.2188	$ 0.50	$ 0.438
Weighted average Common Shares outstanding - basic	83,021	82,262	83,024	82,220
Weighted average Common Shares outstanding - fully diluted	91,128	90,780	91,110	90,774
Cumulative SeriesA Eight Point Zero Three Four Percent Redeemable Perpetual Preferred Stock [Member]
Other comprehensive loss:
Redeemable Preferred Stock Dividends	0	(4,038,000)	0	8,069,000
Cumulative Series C Six Point Seven Five Percent Redeemable Perpetual Preferred Stock [Member]
Other comprehensive loss:
Redeemable Preferred Stock Dividends	(2,329,000)	0	4,640,000	0
Non-controlling interests - Common OP Units
Other comprehensive loss:
Comprehensive income (loss) allocated to non-controlling interests	$ (1,633,000)	$ (195,000)	$ 4,802,000	$ 1,353,000