Business Segments - Segment Reporting, Reconciliation of Revenues, Operating Income and Assets (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total revenues	$ 766,183	$ 602,155	$ 1,395,338	$ 1,208,455
Operating income	275,272	142,348	437,158	271,546
General and administrative expenses	60,077	56,934	113,694	107,477
Depreciation and amortization expenses	228,145	230,382	454,736	480,382
Earnings from unconsolidated entities, net	68,596	41,454	117,201	99,765
Interest expense	(75,354)	(76,455)	(148,266)	(157,267)
Interest and other income, net	1,892	1,527	4,677	4,118
Gains on dispositions of investments in real estate, net	83,006	200,350	180,331	344,667
Foreign currency and derivative losses, net	(20,055)	(10,335)	(27,455)	(24,546)
Gains (losses) on early extinguishment of debt, net	(30,596)	2,044	(30,596)	992
Earnings before income taxes	302,761	300,933	533,050	539,275
Total assets	30,150,395		30,150,395		$ 30,249,932
Investments in and advances to unconsolidated entities	4,617,724		4,617,724		4,230,429
Assets held for sale or contribution	350,987		350,987		322,139
Notes receivable backed by real estate	19,536		19,536		32,100
Cash and cash equivalents	271,354	332,221	271,354	332,221	807,316	$ 264,080
Other assets	1,415,879		1,415,879		1,496,990
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues	766,183	602,155	1,395,338	1,208,455
Operating income	563,494	429,664	1,005,588	859,405
Total assets	24,698,080		24,698,080		24,614,975
Operating Segments [Member] | Real Estate Operations Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	585,529	548,620	1,157,639	1,103,917
Operating income	434,826	403,995	851,674	808,026
Total assets	24,634,988		24,634,988		24,547,949
Operating Segments [Member] | Strategic Capital Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	180,654	53,535	237,699	104,538
Operating income	128,668	25,669	153,914	51,379
Total assets	63,092		63,092		67,026
Operating Segments [Member] | U.S. [Member] | Real Estate Operations Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	529,841	501,707	1,053,988	1,012,864
Operating income	396,274	369,786	780,374	745,503
Total assets	21,295,808		21,295,808		21,286,422
Operating Segments [Member] | U.S. [Member] | Strategic Capital Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	130,677	9,580	142,585	18,936
Operating income	99,668	826	101,607	2,536
Total assets	17,454		17,454		18,090
Operating Segments [Member] | Other Americas [Member] | Real Estate Operations Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	16,444	15,083	31,533	29,018
Operating income	10,384	10,517	20,366	18,710
Total assets	1,052,052		1,052,052		978,476
Operating Segments [Member] | Other Americas [Member] | Strategic Capital Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	9,864	5,693	15,915	11,079
Operating income	7,587	3,052	10,732	6,188
Operating Segments [Member] | Europe [Member] | Real Estate Operations Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	22,076	19,533	40,307	36,008
Operating income	16,401	15,328	29,259	26,633
Total assets	1,139,882		1,139,882		1,346,589
Operating Segments [Member] | Europe [Member] | Strategic Capital Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	25,973	25,526	52,235	48,109
Operating income	16,342	18,450	32,732	34,070
Total assets	44,680		44,680		47,635
Operating Segments [Member] | Asia [Member] | Real Estate Operations Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	17,168	12,297	31,811	26,027
Operating income	11,767	8,364	21,675	17,180
Total assets	1,147,246		1,147,246		936,462
Operating Segments [Member] | Asia [Member] | Strategic Capital Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	14,140	12,736	26,964	26,414
Operating income	5,071	3,341	8,843	8,585
Total assets	958		958		1,301
Reconciling Items [Member]
Segment Reporting Information [Line Items]
Operating income	275,272	142,348	437,158	271,546
General and administrative expenses	60,077	56,934	113,694	107,477
Depreciation and amortization expenses	228,145	230,382	454,736	480,382
Earnings from unconsolidated entities, net	68,596	41,454	117,201	99,765
Interest expense	(75,354)	(76,455)	(148,266)	(157,267)
Interest and other income, net	1,892	1,527	4,677	4,118
Gains on dispositions of investments in real estate, net	83,006	200,350	180,331	344,667
Foreign currency and derivative losses, net	(20,055)	(10,335)	(27,455)	(24,546)
Gains (losses) on early extinguishment of debt, net	(30,596)	$ 2,044	(30,596)	$ 992
Total assets	5,452,315		5,452,315		5,634,957
Investments in and advances to unconsolidated entities	4,617,724		4,617,724		4,230,429
Assets held for sale or contribution	350,987		350,987		322,139
Notes receivable backed by real estate	19,536		19,536		32,100
Cash and cash equivalents	271,354		271,354		807,316
Other assets	$ 192,714		$ 192,714		$ 242,973