Detail of secured and unsecured senior debt (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
Effective rate (as a percent)	3.44%
Future principal payments due on secured and unsecured debt
2022	$ 3,592
2023	3,772
2024	183,559
2025	600,034
2026	930,038
Thereafter	7,125,518
Outstanding Balance	8,846,513
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(54,647)
Total Consolidated	$ 8,791,866
Secured notes payable
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.74%
Effective rate (as a percent)	3.40%
Future principal payments due on secured and unsecured debt
2022	$ 3,592
2023	3,772
2024	183,559
2025	34
2026	10,038
Thereafter	518
Outstanding Balance	201,513
Unamortized Discount (Premium) and Debt Issuance Costs, Net	3,685
Total Consolidated	$ 205,198
Secured notes payable maturing on 2/6/24
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.82%
Effective rate (as a percent)	3.40%
Maturity date	Feb. 06, 2024
Future principal payments due on secured and unsecured debt
2022	$ 3,564
2023	3,742
2024	183,527
2025	0
2026	0
Thereafter	0
Outstanding Balance	190,833
Unamortized Discount (Premium) and Debt Issuance Costs, Net	5,696
Total Consolidated	$ 196,529
Secured notes payable maturing on 11/19/26
Debt Instrument [Line Items]
Effective rate (as a percent)	3.10%
Maturity date	Nov. 19, 2026
Debt instrument, borrowing capacity	$ 185,300
Future principal payments due on secured and unsecured debt
2022	0
2023	0
2024	0
2025	0
2026	10,002
Thereafter	0
Outstanding Balance	10,002
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(2,011)
Total Consolidated	$ 7,991
Secured notes payable maturing on 11/19/26 | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Applicable margin (as a percent)	2.70%
Secured notes payable maturing on 7/1/36
Debt Instrument [Line Items]
Stated interest rate (as a percent)	6.50%
Effective rate (as a percent)	6.50%
Maturity date	Jul. 01, 2036
Future principal payments due on secured and unsecured debt
2022	$ 28
2023	30
2024	32
2025	34
2026	36
Thereafter	518
Outstanding Balance	678
Unamortized Discount (Premium) and Debt Issuance Costs, Net	0
Total Consolidated	$ 678
Unsecured Debt
Debt Instrument [Line Items]
Effective rate (as a percent)	3.44%
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	600,000
2026	920,000
Thereafter	7,125,000
Outstanding Balance	8,645,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(58,332)
Total Consolidated	$ 8,586,668
Unsecured senior line of credit
Debt Instrument [Line Items]
Maturity date	Jan. 06, 2026
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	0
Outstanding Balance	0
Unamortized Discount (Premium) and Debt Issuance Costs, Net	0
Total Consolidated	$ 0
Unsecured senior line of credit | LIBOR
Debt Instrument [Line Items]
Applicable margin (as a percent)	0.815%
3.45% unsecured senior notes payable
Debt Instrument [Line Items]
Stated interest rate (as a percent)	3.45%
Effective rate (as a percent)	3.62%
Maturity date	Apr. 30, 2025
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	600,000
2026	0
Thereafter	0
Outstanding Balance	600,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(2,934)
Total Consolidated	$ 597,066
4.30% unsecured senior notes payable
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.30%
Effective rate (as a percent)	4.50%
Maturity date	Jan. 15, 2026
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	300,000
Thereafter	0
Outstanding Balance	300,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(1,987)
Total Consolidated	$ 298,013
3.80% Unsecured Senior Notes Payable
Debt Instrument [Line Items]
Stated interest rate (as a percent)	3.80%
Effective rate (as a percent)	3.96%
Maturity date	Apr. 15, 2026
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	350,000
Thereafter	0
Outstanding Balance	350,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(2,116)
Total Consolidated	$ 347,884
3.95% unsecured senior notes payable due in 2027
Debt Instrument [Line Items]
Stated interest rate (as a percent)	3.95%
Effective rate (as a percent)	4.13%
Maturity date	Jan. 15, 2027
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	350,000
Outstanding Balance	350,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(2,570)
Total Consolidated	$ 347,430
3.95% unsecured senior notes payable due in 2028
Debt Instrument [Line Items]
Stated interest rate (as a percent)	3.95%
Effective rate (as a percent)	4.07%
Maturity date	Jan. 15, 2028
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	425,000
Outstanding Balance	425,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(2,569)
Total Consolidated	$ 422,431
4.50% unsecured senior notes payable
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.50%
Effective rate (as a percent)	4.60%
Maturity date	Jul. 30, 2029
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	300,000
Outstanding Balance	300,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(1,689)
Total Consolidated	$ 298,311
2.75% Unsecured Senior Notes Payable Due 2029
Debt Instrument [Line Items]
Stated interest rate (as a percent)	2.75%
Effective rate (as a percent)	2.87%
Maturity date	Dec. 15, 2029
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	400,000
Outstanding Balance	400,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(3,284)
Total Consolidated	$ 396,716
4.70% unsecured senior note payable
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.70%
Effective rate (as a percent)	4.81%
Maturity date	Jul. 01, 2030
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	450,000
Outstanding Balance	450,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(3,167)
Total Consolidated	$ 446,833
4.90% Unsecured Senior Notes Payable
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.90%
Effective rate (as a percent)	5.05%
Maturity date	Dec. 15, 2030
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	700,000
Outstanding Balance	700,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(7,067)
Total Consolidated	$ 692,933
3.375% Unsecured Senior Notes Payable
Debt Instrument [Line Items]
Stated interest rate (as a percent)	3.375%
Effective rate (as a percent)	3.48%
Maturity date	Aug. 15, 2031
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	750,000
Outstanding Balance	750,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(6,264)
Total Consolidated	$ 743,736
2.00% Unsecured Senior Notes Payable
Debt Instrument [Line Items]
Stated interest rate (as a percent)	2.00%
Effective rate (as a percent)	2.12%
Maturity date	May 18, 2032
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	900,000
Outstanding Balance	900,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(9,712)
Total Consolidated	$ 890,288
1.875% Unsecured Senior Notes Payable
Debt Instrument [Line Items]
Stated interest rate (as a percent)	1.875%
Effective rate (as a percent)	1.97%
Maturity date	Feb. 01, 2033
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	1,000,000
Outstanding Balance	1,000,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(9,701)
Total Consolidated	$ 990,299
4.85% Unsecured Senior Note Payable
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.85%
Effective rate (as a percent)	4.93%
Maturity date	Apr. 15, 2049
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	300,000
Outstanding Balance	300,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(3,217)
Total Consolidated	$ 296,783
4.00% Unsecured Senior Notes Payables Due 2050
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.00%
Effective rate (as a percent)	3.91%
Maturity date	Feb. 01, 2050
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	700,000
Outstanding Balance	700,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	10,320
Total Consolidated	$ 710,320
3.00% Unsecured Senior Notes Payable
Debt Instrument [Line Items]
Stated interest rate (as a percent)	3.00%
Effective rate (as a percent)	3.08%
Maturity date	May 18, 2051
Future principal payments due on secured and unsecured debt
2022	$ 0
2023	0
2024	0
2025	0
2026	0
Thereafter	850,000
Outstanding Balance	850,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(12,365)
Total Consolidated	$ 837,635
Commercial paper program
Debt Instrument [Line Items]
Stated interest rate (as a percent)	0.29%
Effective rate (as a percent)	0.29%
Maturity date	Jan. 18, 2022
Future principal payments due on secured and unsecured debt
2023	$ 0
2024	0
2025	0
2026	270,000
Thereafter	0
Outstanding Balance	270,000
Unamortized Discount (Premium) and Debt Issuance Costs, Net	(10)
Total Consolidated	$ 269,990