Real Estate and Accumulated Depreciation (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Total per Schedule III	$ 24,178,816	$ 25,375,539	$ 25,608,648	$ 24,178,816	$ 25,375,539
Land				1,154,383
Other real estate investments				505,445
Total per consolidated balance sheet				25,838,644	27,119,330
Aggregate cost for Federal tax purposes				20,000,000
Total accumulated depreciation per Schedule III	3,971,501	3,679,479	3,207,855	3,971,501	3,679,479
Accumulated depreciation on other real estate investments	87,847
Less accumulated depreciation				4,059,348	$ 3,758,372
Amount secured of mortgage notes				2,500,000
Mortgage notes	967,500
Assessment bonds				$ 13,500
Assessment bonds, aggregate undepreciated cost	741,500
Real estate assets:
Balance at beginning of year	25,375,539	25,608,648	20,109,432
Acquisitions of operating properties, improvements to operating properties development activity, transfers of land to CIP and net effect of changes in foreign exchange rates and other	2,680,484	1,883,888	7,191,335
Basis of operating properties disposed of	(3,697,798)	(1,359,186)	(1,719,632)
Change in the development portfolio balance, including the acquisition of properties	161,408	(440,821)	398,923
Assets transferred to held-for-sale	(340,817)	(316,990)	(371,410)
Balance at end year	24,178,816	25,375,539	25,608,648
Accumulated depreciation:
Balance at beginning of year	3,679,479	3,207,855	2,748,835
Depreciation expense	614,756	668,686	617,258
Balances retired upon disposition of operating properties and net effect of changes in foreign exchange rates and other	(313,584)	(195,895)	(153,621)
Assets transferred to held-for-sale	(9,150)	(1,167)	(4,617)
Balance at end of year	$ 3,971,501	$ 3,679,479	$ 3,207,855
Standard Tenant Improvements [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Useful lives for real estate assets	10 years
Land improvements on developed buildings [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Useful lives for real estate assets	25 years
Parque Opcion [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Useful lives for real estate assets	30 years
Properties Developed [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Useful lives for real estate assets	40 years
Minimum [Member] | Capital Improvements [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Useful lives for real estate assets	5 years
Maximum [Member] | Capital Improvements [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Useful lives for real estate assets	7 years