Senior Unsecured Notes and Secured Debt - Summary of Principal Activity (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)
Amount
Debt issued	$ 5,385	$ 0
Ending balance	14,347,236
Senior unsecured notes
Amount
Beginning balance	11,707,961	11,509,533
Debt issued	550,000	750,000
Foreign currency	(26,366)	20,059
Ending balance	$ 12,231,595	$ 12,279,592
Weighted Avg. Interest Rate
Beginning balance	3.67%	3.67%
Debt issued	0.0385	0.0280
Foreign currency	0.0414	0.0390
Ending balance	3.69%	3.62%
Secured debt
Amount
Beginning balance	$ 2,202,312	$ 2,378,073
Debt issued	5,385	0
Debt extinguished	(100,821)	(41,933)
Principal payments	(15,968)	(15,955)
Foreign currency	24,733	15,987
Ending balance	$ 2,115,641	$ 2,336,172
Weighted Avg. Interest Rate
Beginning balance	3.03%	3.27%
Debt issued	0.0308	0
Debt extinguished	0.0421	0.0760
Principal payments	0.0319	0.0359
Foreign currency	0.0273	0.0292
Ending balance	3.02%	3.14%