Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended													12 Months Ended						12 Months Ended							12 Months Ended												12 Months Ended							3 Months Ended		12 Months Ended			12 Months Ended
	Jan. 31, 2011	Sep. 14, 2012	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Mar. 04, 2011	Dec. 31, 2009	Aug. 14, 2008	Dec. 31, 2012 Maximum integer	Dec. 31, 2012 Minimum	Dec. 31, 2012 Natural Disasters and Other Casualty Events	Dec. 31, 2011 Natural Disasters and Other Casualty Events	Dec. 31, 2010 Natural Disasters and Other Casualty Events	Dec. 31, 2012 Fair Value, Inputs, Level 2	Dec. 31, 2011 Fair Value, Inputs, Level 2	Dec. 31, 2012 Florida	Dec. 31, 2011 Florida	Dec. 31, 2010 Florida	Dec. 31, 2012 Arizona	Dec. 31, 2011 Arizona	Dec. 31, 2010 Arizona	Dec. 31, 2012 California	Dec. 31, 2011 California	Dec. 31, 2010 California	Dec. 31, 2012 Chattel Loans	Dec. 31, 2012 Chattel Loans Maximum	Dec. 31, 2011 Segment, Discontinued Operations [Member]	Dec. 31, 2012 Buildings and structural and land improvements	Dec. 31, 2012 Building Improvements	Dec. 31, 2012 Furniture, Fixtures and Equipment	Dec. 31, 2012 Real Estate Rate	Dec. 31, 2011 Preferred Stock	Dec. 31, 2012 8.034% Series A Cumulative Redeemable Perpetual Preferred Stock	Dec. 31, 2011 8.034% Series A Cumulative Redeemable Perpetual Preferred Stock	Dec. 31, 2012 Cumulative Series Eight Point Zero Three Four Percent Redeemable Perpetual Preferred Stock [Member]	Oct. 18, 2012 Cumulative Series Eight Point Zero Three Four Percent Redeemable Perpetual Preferred Stock [Member]	Dec. 31, 2012 Cumulative Series C Six Point Seven Five Percent Redeemable Perpetual Preferred Stock [Member]	Sep. 14, 2012 Cumulative Series C Six Point Seven Five Percent Redeemable Perpetual Preferred Stock [Member]	Dec. 31, 2011 Cumulative Series C Six Point Seven Five Percent Redeemable Perpetual Preferred Stock [Member]	Dec. 31, 2012 Purchase Price Allocation Adjustments	Dec. 31, 2012 Identified Intangible Assets [Member]	Dec. 31, 2011 Identified Intangible Assets [Member]
Significant Accounting Policies [Line Items]
Valuation Allowances and Reserves, Balance			$ 6,987,000				$ 7,700,000				$ 6,580,000				$ 6,987,000	$ 7,700,000	$ 6,580,000		$ 5,795,000
Ordinary Income Dividends Per Share	$ 1.125														$ 1.619		$ 1.15
Loans Receivable Default Rate			23.00%												23.00%
Loans Receivable Recovery Rate			26.00%												26.00%
Dividends Payable, Date to be Paid			Dec. 28, 2012	Oct. 12, 2012	Jul. 13, 2012	Apr. 13, 2012	Jan. 13, 2012	Oct. 14, 2011	Jul. 08, 2011	Apr. 08, 2011	Jan. 14, 2011	Oct. 08, 2010	Jul. 09, 2010	Apr. 09, 2010
Investment percentage to apply cost method accounting, maximum																					5.00%
Intangible Assets, Net (Including Goodwill)			12,100,000				12,100,000								12,100,000	12,100,000
Final Adjustment Period Maximum Range																																																				1 year
Number of Reportable Segments																					2
Estimated useful life																																								30 years	10 years	5 years	20 years
Disposal of Intangable assets							3,500,000									3,500,000
Intangible assets			4,300,000				4,300,000								4,300,000	4,300,000
Goodwill			7,800,000				7,800,000								7,800,000	7,800,000
Accumulated amortization of identified intangible assets			1,500,000				1,200,000								1,500,000	1,200,000																							2,000,000
Amortization of Intangible Assets															45,122,000	28,479,000	0																																				300,000	1,900,000
Goodwill impairment															0	0	3,635,000
Cash and cash equivalents, restricted cash			4,900,000				4,200,000								4,900,000	4,200,000
Accumulated amortization for deferred financing costs			20,500,000				15,100,000								20,500,000	15,100,000
Non-Controlling Interests - Common OP Units			3,728,160				4,103,067				4,914,040				3,728,160	4,103,067	4,914,040
Net investment in real estate U.S federal tax basis			2,800,000,000												2,800,000,000
Net investment in notes receivable U.S federal tax basis			58,700,000												58,700,000
Loans receivable, amortization term																																					14 years	29 years
Estimated claims from hurricanes																							21,000,000
Number of properties suffered from hurricanes damage																				82			70
Proceeds from insurance carriers															15,200,000
Gain on insurance recovery, net															400,000	2,600,000	300,000
Contingent legal fees																							100,000	900,000	200,000
Mortgage notes payable, fair value																										2,200,000,000	2,200,000,000
Provision for uncollectable rents receivable			4,700,000				4,900,000								4,700,000	4,900,000
Rental income recognition period																					1 year
Percentage of company revenue																												39.40%	38.50%	37.60%	9.40%	10.80%	11.50%	15.20%	17.80%	19.40%
Deferred revenue, estimated period of recognition																					31 years	1 year
Right-to-use properties contract, term																						1 year
Private REIT Subsidiaries preferred stock			65,054,000				72,953,000								65,054,000	72,953,000																												700,000
Cumulative Redeemable Preferred Stock, shares issued			0				8,000,000								0	8,000,000		8,000,000
Cumulative Redeemable Preferred Stock, par value			$ 0.01				$ 0.01								$ 0.01	$ 0.01		$ 0.01
Cumulative Redeemable Preferred Stock, liquidation preference per share																		$ 25.00
Cumulative Redeemable Preferred Stock, dividend rate																																																	6.75%
Cumulative Redeemable Preferred Stock, conversion price per share																		$ 24.75
Cumulative Redeemable Preferred Stock, redemption price per share																		$ 25.00
Perpetual Preferred OP Units conversion															0	200,000,000	0
Quarterly distribution paid per common share			$ 0.4375	$ 0.4375	$ 0.4375	$ 0.4375	$ 0.3750	$ 0.3750	$ 0.3750	$ 0.3750	$ 0.3000	$ 0.3000	$ 0.3000	$ 0.3000	$ 0.4375
Property, Plant and Equipment, Salvage Value, Percentage																																											40.00%
Preferred Stock, Shares Authorized			9,945,542				2,000,000								9,945,542	2,000,000																													0	0			54,461	54,458	0
Preferred Stock, Liquidation Preference Per Share																																																$ 25.00		$ 2,500.00
Peferred Stock, Shares Exchanged		5,445,765
Depositary Shares, Issued		5,445,765
Depositary Share, Liquidation Preference Per Share		$ 25.00
Preferred Stock, Dividend Rate, Per-Dollar-Amount		$ 0.3849625	$ 0.0948460
Stock Redeemed or Called During Period, Shares																																															2,554,235
Stock Redeemed or Called During Period, Value																																															64,100,000
Capital Gains Dividends Per Share	$ 0.000														$ 0.137		$ 0.05
Nondividend Distribution	$ 0.000														$ 0.369		$ 0.00
Common Stock Dividends Per Share Tax Treatment	$ 1.125														$ 2.125		$ 1.20
Valuation Allowances and Reserves, Charged to Cost and Expense															4,860,000	4,156,000	3,063,000
Valuation Allowances and Reserves, Deductions															$ (5,573,000)	$ (3,036,000)	$ (2,278,000)