Debt - Debt Summary (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Weighted Average Interest Rate	2.20%	2.70%
Debt	$ 11,905,877	$ 11,089,815
Credit Facilities [Member]
Debt Instrument [Line Items]
Weighted Average Interest Rate	0.40%	3.40%
Debt	$ 184,255	$ 50,500
Senior Notes [Member]
Debt Instrument [Line Items]
Weighted Average Interest Rate	2.40%	2.70%
Debt	$ 9,660,570	$ 8,304,147
Term Loans and Unsecured Other [Member]
Debt Instrument [Line Items]
Weighted Average Interest Rate	0.90%	1.80%
Debt	$ 1,441,882	$ 1,921,428
Secured Mortgage [Member]
Debt Instrument [Line Items]
Weighted Average Interest Rate	3.40%	5.10%
Debt	$ 619,170	$ 813,740