v3.25.2
Fair value measurements - Assets and Liabilities on Recurring and Nonrecurring Basis (Details)
$ in Thousands
6 Months Ended
Jun. 30, 2025
USD ($)
transfer
Dec. 31, 2024
USD ($)
Assets and liabilities measured at fair value    
Transfers in Fair Value Hierarchy | transfer 0  
Disposal Group, Including Assets Held For Sale Not Qualifying As Discontinued Operations, Net Assets $ 323,666 $ 371,257
Investments 1,476,696 1,476,985
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Secured notes payable 153,500 149,909
Unsecured senior notes payable 12,042,607 12,094,465
Book value    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Secured notes payable 153,500 149,909
Unsecured senior notes payable 12,042,607 12,094,465
Book value | Commercial Paper    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Commercial Paper 1,097,993 0
Book value | Unsecured senior line of credit    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Unsecured senior lines of credit 0 0
Fair Value | Fair value measured on nonrecurring basis    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Real Estate, Held-for-Sale 289,673 322,662
Secured notes payable, fair value 153,521 149,413
Unsecured senior notes payable, fair value 10,548,383 10,472,993
Fair Value | Fair value measured on nonrecurring basis | Commercial Paper    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Commercial paper, fair value disclosure 1,098,989 0
Fair Value | Fair value measured on nonrecurring basis | Unsecured senior line of credit    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Unsecured senior lines of credit, fair value 0 0
Fair Value | Fair value measured on nonrecurring basis | Quoted prices in active markets for identical assets (Level 1)    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Long-Lived Asset, Held-for-Sale, Fair Value Disclosure 0 0
Secured notes payable, fair value 0 0
Unsecured senior notes payable, fair value 0 0
Fair Value | Fair value measured on nonrecurring basis | Quoted prices in active markets for identical assets (Level 1) | Commercial Paper    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Commercial paper, fair value disclosure 0 0
Fair Value | Fair value measured on nonrecurring basis | Quoted prices in active markets for identical assets (Level 1) | Unsecured senior line of credit    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Unsecured senior lines of credit, fair value 0 0
Fair Value | Fair value measured on nonrecurring basis | Significant other observable inputs (Level 2)    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Long-Lived Asset, Held-for-Sale, Fair Value Disclosure 0 0
Secured notes payable, fair value 153,521 149,413
Unsecured senior notes payable, fair value 10,548,383 10,472,993
Fair Value | Fair value measured on nonrecurring basis | Significant other observable inputs (Level 2) | Commercial Paper    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Commercial paper, fair value disclosure 1,098,989 0
Fair Value | Fair value measured on nonrecurring basis | Significant other observable inputs (Level 2) | Unsecured senior line of credit    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Unsecured senior lines of credit, fair value 0 0
Fair Value | Fair value measured on nonrecurring basis | Significant unobservable input (Level 3)    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Long-Lived Asset, Held-for-Sale, Fair Value Disclosure 289,673 322,662
Secured notes payable, fair value 0 0
Unsecured senior notes payable, fair value 0 0
Fair Value | Fair value measured on nonrecurring basis | Significant unobservable input (Level 3) | Commercial Paper    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Commercial paper, fair value disclosure 0 0
Fair Value | Fair value measured on nonrecurring basis | Significant unobservable input (Level 3) | Unsecured senior line of credit    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Unsecured senior lines of credit, fair value 0 0
Investments in publicly traded companies    
Assets and liabilities measured at fair value    
Investments at fair value 81,925 105,667
Investments in publicly traded companies | Fair Value | Fair value measured on recurring basis    
Assets and liabilities measured at fair value    
Investments at fair value 81,925 105,667
Investments in publicly traded companies | Fair Value | Fair value measured on recurring basis | Quoted prices in active markets for identical assets (Level 1)    
Assets and liabilities measured at fair value    
Investments at fair value 81,925 105,667
Investments in publicly traded companies | Fair Value | Fair value measured on recurring basis | Significant other observable inputs (Level 2)    
Assets and liabilities measured at fair value    
Investments at fair value 0 0
Investments in publicly traded companies | Fair Value | Fair value measured on recurring basis | Significant unobservable input (Level 3)    
Assets and liabilities measured at fair value    
Investments at fair value 0 0
Investments in privately held entities that report NAV    
Assets and liabilities measured at fair value    
Investments at fair value 552,163 609,866
Entities without observable price changes | Investments in privately held entities that do not report NAV    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Investments in privately held entities that do not report fair value, book value 432,299 400,487
Entities without observable price changes | Investments in privately held entities that do not report NAV | Fair Value | Fair value measured on nonrecurring basis    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Investments in privately held entities that do not report fair value, book value 150,943 184,236
Entities without observable price changes | Investments in privately held entities that do not report NAV | Fair Value | Fair value measured on nonrecurring basis | Quoted prices in active markets for identical assets (Level 1)    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Investments in privately held entities that do not report fair value, book value 0 0
Entities without observable price changes | Investments in privately held entities that do not report NAV | Fair Value | Fair value measured on nonrecurring basis | Significant other observable inputs (Level 2)    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Investments in privately held entities that do not report fair value, book value 133,534 174,737
Entities without observable price changes | Investments in privately held entities that do not report NAV | Fair Value | Fair value measured on nonrecurring basis | Significant unobservable input (Level 3)    
Fair Value Measurements, Nonrecurring Value Measurement [Abstract]    
Investments in privately held entities that do not report fair value, book value $ 17,409 $ 9,499