v3.26.1
Financial Highlights (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Mar. 31, 2025
Per Accumulation Unit Data:          
Rental income (in dollars per share) $ 6.547 $ 26.577 $ 28.407 $ 27.323  
Real estate property level expenses (in dollars per share) 2.955 11.694 13.098 12.858  
Real estate income, net (in dollars per share) 3.592 14.883 15.309 14.465  
Other income (in dollars per share) 1.554 6.533 7.209 7.539  
Total income (in dollars per share) 5.146 21.416 22.518 22.004  
Interest expense (in dollars per share) 0.446 1.225 1.117 1.339  
Expense charges (in dollars per share) 1.110 4.217 4.701 4.877  
Investment income, net (in dollars per share) 3.590 15.974 16.700 15.788  
Net realized and unrealized gain (loss) on investments and debt (in dollars per share) (0.649) 2.341 (36.511) (91.657)  
Net increase (decrease) in Accumulation Unit Value (in dollars per share) 2.941 18.315 (19.811) (75.869)  
Accumulation Unit Value:          
Beginning of period (in dollars per share) 479.558 461.243 481.054 556.923  
End of period (in dollars per share) $ 482.499 $ 479.558 $ 461.243 $ 481.054  
Total return 0.61% 3.97% (4.12%) (13.62%)  
Ratios to Average net assets:          
Expense charges 0.92% 0.88% 0.99% 0.93%  
Investment income, net 2.97% 3.32% 3.52% 3.00%  
Portfolio turnover rate:          
Real estate properties 1.50% 6.90% 2.70% 1.40%  
Marketable securities 0.00% 0.00% 23.60% 21.60%  
Accumulation Units outstanding at end of period (millions) (in shares) 46.2 46.5 47.8 48.0  
Net assets end of period (millions) $ 22,736.2 $ 22,766.6 $ 22,486.9 $ 23,618.9 $ 22,580.6