Real Estate and Accumulated Depreciation (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Total per Schedule III	$ 25,608,648	$ 20,109,432	$ 18,822,081	$ 25,608,648	$ 20,109,432
Land				1,359,794
Other real estate investments	552,926
Total per consolidated balance sheet				27,521,368	22,190,145
Aggregate cost for Federal tax purposes				16,900,000
Total accumulated depreciation per Schedule III	3,207,855	2,748,835	2,540,267	3,207,855	2,748,835
Accumulated depreciation on other real estate investments				66,429
Less accumulated depreciation				3,274,284	$ 2,790,781
Amount secured of mortgage notes				5,800,000
Mortgage notes	3,000,000
Assessment bonds				$ 15,200
Assessment bonds, aggregate undepreciated cost	843,800
Real estate assets:
Balance at beginning of year	20,109,432	18,822,081	23,559,891
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	7,191,335	3,595,836	2,050,810
Basis of operating properties disposed of	(1,719,632)	(2,713,300)	(6,857,994)
Change in the development portfolio balance, including the acquisition of properties	398,923	452,963	69,374
Assets transferred to held-for-sale	(371,410)	(48,148)	0
Balance at end year	25,608,648	20,109,432	18,822,081
Accumulated depreciation:
Balance at beginning of year	2,748,835	2,540,267	2,460,642
Depreciation expense	617,258	490,298	505,691
Balances retired upon disposition of operating properties and net effect of changes in foreign exchange rates and other	(153,621)	(277,516)	(426,066)
Assets transferred to held-for-sale	(4,617)	(4,214)	0
Balance at end of year	$ 3,207,855	$ 2,748,835	$ 2,540,267
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
Acquired Industrial Properties [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