Debt - Debt Summary (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Weighted Average Interest Rate	2.20%	2.20%
Debt	$ 15,676,592	$ 11,905,877
Credit Facilities [Member]
Debt Instrument [Line Items]
Weighted Average Interest Rate	0.40%	0.40%
Debt	$ 52,522	$ 184,255
Senior Notes [Member]
Debt Instrument [Line Items]
Weighted Average Interest Rate	2.30%	2.40%
Debt	$ 13,045,081	$ 9,660,570
Term Loans and Unsecured Other [Member]
Debt Instrument [Line Items]
Weighted Average Interest Rate	1.10%	0.90%
Debt	$ 1,930,955	$ 1,441,882
Secured Mortgage [Member]
Debt Instrument [Line Items]
Weighted Average Interest Rate	3.70%	3.40%
Debt	$ 648,034	$ 619,170