Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Significant Accounting Policies [Line Items]
Total real estate assets, net	$ 6,968,394,000	$ 6,719,063,000
Deconsolidation Gain Or Loss Amounts		4,700,000	5,600,000
Retained interest in joint venture investment subsequent to deconsolidation		0
Capitalized costs	10,500,000	9,100,000	9,700,000
Aggregated liability of below-market leases	50,400,000	29,500,000
Aggregated asset of above-market leases	17,700,000	2,800,000
Future Amortization income, 2013	100,000
Future Amortization income, 2014	500,000
Future Amortization income, 2015	700,000
Future Amortization income, 2016	1,400,000
Future Amortization income, 2017	2,100,000
Impairment charges related to consolidated real estate investment	126,500,000	125,800,000	171,900,000
Interest paid	209,300,000	218,600,000	221,500,000
Capitalized interest paid	13,300,000	12,700,000	12,200,000
Impairment of joint venture investments	26,671,000	2,921,000	227,000
Accounts receivable, unrecoverable amount	10,800,000	19,300,000
Allowance for straight line rent	3,600,000	3,200,000
Straight line rent receivable, net	58,200,000	55,700,000
Valuation allowance			(58,300,000)
Stock-based compensation cost recognized by the company	6,400,000	6,800,000	5,700,000
Accelerated vesting of awards due to employee severance charges	200,000	1,600,000	400,000
Variable Interest Entity, Primary Beneficiary [Member]
Significant Accounting Policies [Line Items]
Total real estate assets, net	184,600,000	289,500,000
Mortgages	21,500,000	23,500,000
Other real estate liabilities	$ 1,900,000	$ 28,700,000