Line of credit and commercial paper program (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Jul. 31, 2023	Sep. 22, 2022
Debt Instrument [Line Items]
Long-term Debt		$ 12,400,555
Repayments of Secured Debt		$ 154,212	$ 32	$ 30
Effective rate (as a percent)		3.91%
Loss on early extinguishment of debt		$ (107)	$ 0	$ 0
Unsecured senior line of credit
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 5,000,000
Debt Instrument, Basis Spread on Variable Rate		0.855%	0.875%
Annual facility fee (as a percent)		0.145%	0.15%
Debt Instrument, Interest Rate Adjustment Amount, Maximum						0.04%
Debt Instrument, Facility Fee Rate Adjustment Amount, Maximum						0.01%
Debt Instrument, Basis Spread on Variable Rate, Period Increase (Decrease)		0.02%
Line of Credit Facility, Commitment Fee Percentage, Period Increase (Decrease)		0.005%
Long-term Debt		$ 0
Secured notes payable maturing on 11/19/26 | 99 Coolidge Avenue
Debt Instrument [Line Items]
Repayments of Secured Debt	$ 154,600
Effective rate (as a percent)	7.18%
Loss on early extinguishment of debt		$ 107
Commercial paper program
Debt Instrument [Line Items]
Commercial paper, maximum issuance					$ 2,500,000
Weighted-average yield to maturity, commercial paper		4.48%
Weighted-average remaining maturity term, commercial paper		19 days
Outstanding Balance		$ 353,200
Commercial paper program | Unsecured senior line of credit
Debt Instrument [Line Items]
Long-term Debt		353,161
Outstanding Balance		$ 353,500
Effective rate (as a percent)		4.33%
Maximum | Commercial paper program
Debt Instrument [Line Items]
Debt instrument term		397 days
Minimum | Commercial paper program
Debt Instrument [Line Items]
Debt instrument term		30 days