Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash Flows From Operating Activities:
Consolidated net income	$ 74,458	$ 42,504	$ 60,397
Adjustments to reconcile net income to net cash provided by operating activities:
Loss (gain) on sale of discontinued real estate and other	(4,596)	0	231
Depreciation expense	105,578	85,235	72,129
Amortization of in-place leases	(45,122)	(28,479)	0
Amortization loan cost	5,754	5,305	3,325
Debt premium amortization	(6,764)	(1,817)	13
Equity in income of unconsolidated joint ventures	(1,899)	(1,948)	(2,027)
Distributions from unconsolidated joint ventures	1,839	1,841	2,831
Amortization of stock-related compensation	5,797	5,762	5,436
Revenue recognized from right-to-use contract upfront payment	(6,739)	(5,920)	(4,640)
Commission expense recognized related to right-to-use contracts	2,310	1,946	1,432
Accrued long term incentive plan compensation	782	1,813	725
Increase in provision for uncollectible rents receivable	3,243	3,569	2,714
Changes in assets and liabilities:
Notes receivable activity, net	409	477	494
Rent and other customer receivables, net	(3,264)	(4,305)	(2,713)
Inventory	1,379	25	(391)
Deferred commission expense	(5,465)	(6,735)	(6,957)
Escrow deposits and other assets	7,879	(6,113)	11,645
Goodwill impairment	0	0	3,635
Accrued payroll and other operating expenses	(3,041)	6,736	(7,886)
Deferred revenue-upfront payments from right-to-use contracts	13,433	17,856	19,496
Deferred revenue-right-to-use annual payments	(789)	(765)	39
Rents received in advance and security deposits	1,033	1,696	3,381
Net cash provided by operating activities	236,459	175,641	163,309
Cash Flows From Investing Activities:
Acquisition of real estate and other	(24,213)	(651,089)	0
Acquisition of notes receivable	0	(40,362)	0
Proceeds from disposition of rental properties and other	7,564	252	0
Net tax-deferred exchange withdrawal (deposit)	0	0	786
Proceeds from (purchase of) short-term investments	0	52,266	(52,266)
Net (borrowings) repayments of notes receivable	5,344	(883)	1,176
Capital improvements	(75,260)	(62,032)	(48,629)
Net cash used in investing activities	(86,565)	(701,848)	(98,933)
Cash Flows From Financing Activities:
Net proceeds from stock options and employee stock purchase plan	4,932	5,484	2,182
Net proceeds from issuance of Common Stock	0	344,049	0
Payments of Ordinary Dividends, Common Stock	(89,489)	(49,483)	(36,840)
Payments of Ordinary Dividends, Noncontrolling Interest	(6,696)	(6,313)	(5,620)
Stock repurchase and Unit redemption	(1,287)	(1,682)	(2,054)
Acquisition of non-controlling interests	0	0	(1,581)
Distributions to Preferred Unit Holders	0	(2,801)	(16,140)
Payments of Ordinary Dividends, Preferred Stock and Preference Stock	(14,613)	(13,823)	0
Lines of credit:
Proceeds	0	50,000	0
Repayments	0	(50,000)	0
Principal payments and mortgage debt payoff	(167,552)	(75,658)	(211,656)
New mortgage notes payable financing proceeds	159,500	200,000	76,615
Term loan financing proceeds	0	200,000	0
Debt issuance costs	(3,062)	(15,765)	(1,751)
Net cash provided by (used in) financing activities	(183,214)	584,008	(196,845)
Proceeds from Noncontrolling Interests	170	0	0
Payments for Repurchase of Preferred Stock and Preference Stock	(63,856)	0	0
Net increase (decrease) in cash and cash equivalents	(33,320)	57,801	(132,469)
Cash and cash equivalents, beginning of year	70,460	12,659	145,128
Cash and cash equivalents, end of year	37,140	70,460	12,659
Supplemental Information:
Cash paid during the period for interest	118,931	99,816	87,888
Non-cash activities (increase (decrease)):
Manufactured homes acquired with dealer financing	0	830	3,674
Dealer financing	0	830	3,674
Capital improvements	5,313	2,685	566
Net repayments of notes receivable	(5,313)	(2,685)	(566)
Series A Cumulative Redeemable Perpetual Preferred Stock	0	200,000	0
Perpetual Preferred OP Units conversion	0	200,000	0
Acquisitions
Escrow deposits and other assets	6,774	0	0
Accrued payroll and other operating expenses	376	2,643	(164)
Accrued interest payable	0	114	0
Noncash or Part Noncash Acquisition, Accounts Receivable Acquired	29	0	0
Notes receivable	0	0	(2,556)
Rents and other customer payments received in advance and security deposits	440	4,800	(76)
Noncash or Part Noncash Acquisition, Fixed Assets Acquired	18,738	1,431,339	2,796
Debt assumed and financed on acquisition	0	548,410	0
Dispositions
Other assets and liabilities, net	0	252	(97)
Investment in real estate	(2,968)	0	(3,531)
Mortgage notes payable assumed by purchaser	0	0	(3,628)
Equity issuance costs	(1,261)	0	0
Building and other depreciable property – reclassification of rental homes	4,127	2,371	3,915
Escrow deposits and other assets – reclassification of rental homes	(4,127)	(2,371)	(3,915)
Series A Cumulative Redeemable Perpetual Preferred Stock Exchange	(136,144)	0	0
Series C Cumulative Redeemable Perpetual Preferred Stock Exchange	136,144	0	0
Common Stock issued	0	110,495	0
Series B Subordinated Non-Voting Cumulative Redeemable Preferred Stock Issued	$ 0	$ 113,788	$ 0