Mortgage Notes Payable, Unsecured Notes and Credit Facility - Payments and Maturities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 8,170,431		$ 7,629,814
Unsecured notes
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	7,400,000
Unsecured notes | Notes payable maturing in 2022
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 100,000
Stated interest rate (as a percent)		2.95%
Unsecured notes | Variable Rate Unsecured Term Loan $100 Million | LIBOR
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)	0.90%
Unsecured notes | Notes Payable 4.200 Maturities 2023
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 350,000
Stated interest rate (as a percent)	4.20%
Unsecured notes | Notes Payable 2.850 Maturities 2023
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 250,000
Stated interest rate (as a percent)	2.85%
Unsecured notes | Notes Payable 2024
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 300,000
Stated interest rate (as a percent)	3.50%
Unsecured notes | Variable Rate Unsecured Term Loan $150 Million
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 150,000
Unsecured notes | Variable Rate Unsecured Term Loan $150 Million | LIBOR
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Debt instrument, basis spread on variable rate (as a percent)	0.85%
Unsecured notes | Notes Payable 3.450 Maturities 2025
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 525,000
Stated interest rate (as a percent)	3.45%
Unsecured notes | Notes Payable 3.500 Maturities 2025
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 300,000
Stated interest rate (as a percent)	3.50%
Unsecured notes | Notes Payable 2.950 Maturities 2026
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 475,000
Stated interest rate (as a percent)	2.95%
Unsecured notes | Notes Payable 2.900 Maturities 2026
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 300,000
Stated interest rate (as a percent)	2.90%
Unsecured notes | Notes Payable Maturities 2027
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 400,000
Stated interest rate (as a percent)	3.35%
Unsecured notes | Notes Payable Maturities 2028
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 450,000
Stated interest rate (as a percent)	3.20%
Unsecured notes | Notes Payable 1.900 Maturities 2028
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 400,000
Stated interest rate (as a percent)	1.90%
Unsecured notes | Notes Payable Maturities 2029
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 450,000
Stated interest rate (as a percent)	3.30%
Unsecured notes | Notes Payable Maturities 2030
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 700,000
Stated interest rate (as a percent)	2.30%
Unsecured notes | Notes Payable Maturities 2031
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 600,000
Stated interest rate (as a percent)	2.45%
Unsecured notes | Notes Payable Maturities 2032
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 700,000
Stated interest rate (as a percent)	2.05%
Unsecured notes | Notes Payable Maturities 2046
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 350,000
Stated interest rate (as a percent)	3.90%
Unsecured notes | Notes Payable Maturities 2047
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 300,000
Stated interest rate (as a percent)	4.15%
Unsecured notes | Notes Payable Maturities 2048
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Mortgage notes payable and unsecured notes	$ 300,000
Stated interest rate (as a percent)	4.35%
Secured notes
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes principal payments	$ 222,583
Mortgage notes payable and unsecured notes	547,848
Secured notes | Notes payable maturing in 2022
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes principal payments	8,263
Mortgage notes payable and unsecured notes	0
Secured notes | Notes Payable Maturities 2023
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes principal payments	8,999
Mortgage notes payable and unsecured notes	0
Secured notes | Notes Payable 2024
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes principal payments	9,837
Mortgage notes payable and unsecured notes	0
Secured notes | Notes Payable Maturities 2025
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes principal payments	10,478
Mortgage notes payable and unsecured notes	0
Secured notes | Notes Payable Maturities 2026
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes principal payments	11,420
Mortgage notes payable and unsecured notes	0
Secured notes | Notes Payable Maturities 2027
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes principal payments	13,765
Mortgage notes payable and unsecured notes	236,100
Secured notes | Notes Payable Maturities 2028
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes principal payments	18,512
Mortgage notes payable and unsecured notes	0
Secured notes | Notes Payable Maturities 2029
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes principal payments	9,462
Mortgage notes payable and unsecured notes	66,250
Secured notes | Notes Payable Maturities 2030
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes principal payments	10,014
Mortgage notes payable and unsecured notes	0
Secured notes | Notes Payable Maturities 2031
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes principal payments	10,669
Mortgage notes payable and unsecured notes	0
Secured notes | Notes Payable Maturities Thereafter
Mortgage Notes Payable, Unsecured Notes and Credit Facility
Secured notes principal payments	111,164
Mortgage notes payable and unsecured notes	$ 245,498