Debt - Debt Summary (Parenthetical) (Detail) $ in Thousands, € in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) Property	Dec. 31, 2019 EUR (€) Property	Dec. 31, 2018 USD ($)
Debt Instrument [Line Items]
Debt	$ 11,905,877		$ 11,089,815
Number of operating properties securing mortgage debt of consolidated entities | Property	87	87
Number of prestablized properties securing mortgage debt of consolidated entities | Property	1	1
Number of properties under development securing mortgage debt of consolidated entities | Property	1	1
Mortgage notes, aggregate cost of secured properties	$ 1,700,000
Senior Notes [Member]
Debt Instrument [Line Items]
Debt	9,660,570		8,304,147
Principal Amount	$ 445,900	€ 400
Interest rate, Description	Euribor plus 0.3%
Interest rate	0.30%
Secured Mortgage [Member]
Debt Instrument [Line Items]
Debt	$ 619,170		813,740
Minimum [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Effective Interest Rate	0.10%	0.10%
Debt instrument, maturity date	2020-01
Minimum [Member] | Secured Mortgage [Member]
Debt Instrument [Line Items]
Effective Interest Rate	0.20%	0.20%
Debt instrument, maturity date	2020-04
Maximum [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Effective Interest Rate	4.50%	4.50%
Debt instrument, maturity date	2049-09
Maximum [Member] | Secured Mortgage [Member]
Debt Instrument [Line Items]
Effective Interest Rate	7.80%	7.80%
Debt instrument, maturity date	2027-11
GBP
Debt Instrument [Line Items]
Debt	$ 656,549		$ 635,972
Percentage of outstanding debt	5.50%	5.50%	5.80%
CAD
Debt Instrument [Line Items]
Debt	$ 279,730		$ 266,337
Percentage of outstanding debt	2.30%	2.30%	2.40%
EUR
Debt Instrument [Line Items]
Debt	$ 6,128,986		$ 4,893,693
Percentage of outstanding debt	51.50%	51.50%	44.10%
JPY
Debt Instrument [Line Items]
Debt	$ 2,329,381		$ 1,951,844
Percentage of outstanding debt	19.60%	19.60%	17.60%
USD
Debt Instrument [Line Items]
Debt	$ 2,511,231		$ 3,341,969
Percentage of outstanding debt	21.10%	21.10%	30.10%