Business Segments - Segment Reporting, Reconciliation of Revenues, Operating Income and Assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total revenues	$ 629,155	$ 606,300
Operating income	161,886	129,198
General and administrative expenses	53,617	50,543
Depreciation and amortization expenses	226,591	250,000
Earnings from unconsolidated entities, net	48,605	58,311
Interest expense	(72,912)	(80,812)
Interest and other income, net	2,785	2,591
Gains on dispositions of investments in real estate, net	97,325	144,317
Foreign currency and derivative losses, net	(7,400)	(14,211)
Losses on early extinguishment of debt, net	0	(1,052)
Earnings before income taxes	230,289	238,342
Total assets	29,814,958		$ 30,249,932
Investments in and advances to unconsolidated entities	4,305,881		4,230,429
Assets held for sale or contribution	439,743		322,139
Notes receivable backed by real estate	17,006		32,100
Cash and cash equivalents	395,829	369,737	807,316	$ 264,080
Other assets	1,440,087		1,496,990
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	629,155	606,300
Operating income	442,094	429,741
Total assets	24,445,320		24,614,975
Operating Segments [Member] | Real Estate Operations Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	572,110	555,297
Operating income	416,848	404,031
Total assets	24,382,606		24,547,949
Operating Segments [Member] | Strategic Capital Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	57,045	51,003
Operating income	25,246	25,710
Total assets	62,714		67,026
Operating Segments [Member] | U.S. [Member] | Real Estate Operations Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	524,147	511,157
Operating income	384,100	375,717
Total assets	21,276,254		21,286,422
Operating Segments [Member] | U.S. [Member] | Strategic Capital Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	11,908	9,356
Operating income	1,939	1,710
Total assets	17,772		18,090
Operating Segments [Member] | Other Americas [Member] | Real Estate Operations Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	15,089	13,935
Operating income	9,982	8,193
Total assets	1,005,827		978,476
Operating Segments [Member] | Other Americas [Member] | Strategic Capital Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	6,051	5,386
Operating income	3,145	3,136
Operating Segments [Member] | Europe [Member] | Real Estate Operations Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	18,231	16,475
Operating income	12,858	11,305
Total assets	1,119,860		1,346,589
Operating Segments [Member] | Europe [Member] | Strategic Capital Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	26,262	22,583
Operating income	16,390	15,620
Total assets	43,781		47,635
Operating Segments [Member] | Asia [Member] | Real Estate Operations Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	14,643	13,730
Operating income	9,908	8,816
Total assets	980,665		936,462
Operating Segments [Member] | Asia [Member] | Strategic Capital Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	12,824	13,678
Operating income	3,772	5,244
Total assets	1,161		1,301
Reconciling Items [Member]
Segment Reporting Information [Line Items]
Operating income	161,886	129,198
General and administrative expenses	53,617	50,543
Depreciation and amortization expenses	226,591	250,000
Earnings from unconsolidated entities, net	48,605	58,311
Interest expense	(72,912)	(80,812)
Interest and other income, net	2,785	2,591
Gains on dispositions of investments in real estate, net	97,325	144,317
Foreign currency and derivative losses, net	(7,400)	(14,211)
Losses on early extinguishment of debt, net	0	$ (1,052)
Total assets	5,369,638		5,634,957
Investments in and advances to unconsolidated entities	4,305,881		4,230,429
Assets held for sale or contribution	439,743		322,139
Notes receivable backed by real estate	17,006		32,100
Cash and cash equivalents	395,829		807,316
Other assets	$ 211,179		$ 242,973