v3.26.1
CONDENSED CONSOLIDATED SCHEDULES OF INVESTMENTS - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Schedule of Investments [Line Items]    
Fair Value $ 25,365.9 $ 25,405.5
% of Net Assets 110.50% 111.50%
Total investments at cost $ 22,100.3 $ 22,373.0
Marketable Securities    
Schedule of Investments [Line Items]    
Fair Value $ 1,655.8 $ 1,728.7
% of Net Assets 7.20% 7.50%
Total investments at cost $ 1,656.2 $ 1,728.6
Real Estate Funds    
Schedule of Investments [Line Items]    
Fair Value $ 806.2 $ 839.6
% of Net Assets 3.50% 3.70%
Total investments at cost $ 935.6 $ 918.3
Real Estate Operating Business    
Schedule of Investments [Line Items]    
Fair Value $ 1,245.1 $ 1,072.6
% of Net Assets 5.40% 4.70%
Total investments at cost $ 623.5 $ 621.8
Loans Receivable    
Schedule of Investments [Line Items]    
Fair Value $ 432.2 $ 620.1
% of Net Assets 1.90% 2.70%
Total investments at cost $ 707.4 $ 945.1
Loans Receivable with Related Parties    
Schedule of Investments [Line Items]    
Fair Value $ 41.8 $ 70.3
% of Net Assets 0.20% 0.30%
Total investments at cost $ 41.8 $ 70.3
Investment, Identifier [Axis]: Real Estate Joint Ventures, Arizona    
Schedule of Investments [Line Items]    
Fair Value $ 32.2 $ 31.7
% of Net Assets 0.10% 0.10%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Arizona, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 32.2 $ 31.7
% of Net Assets 0.10% 0.10%
Investment, Identifier [Axis]: Real Estate Joint Ventures, California    
Schedule of Investments [Line Items]    
Fair Value $ 723.7 $ 635.9
% of Net Assets 3.20% 2.80%
Investment, Identifier [Axis]: Real Estate Joint Ventures, California, Office    
Schedule of Investments [Line Items]    
Fair Value $ 647.2 $ 597.2
% of Net Assets 2.80% 2.60%
Investment, Identifier [Axis]: Real Estate Joint Ventures, California, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 76.5 $ 38.7
% of Net Assets 0.40% 0.20%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Florida    
Schedule of Investments [Line Items]    
Fair Value $ 386.2 $ 398.6
% of Net Assets 1.70% 1.80%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Florida, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 386.2 $ 398.6
% of Net Assets 1.70% 1.80%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Foreign    
Schedule of Investments [Line Items]    
Fair Value [1] $ 169.3 $ 166.6
% of Net Assets [1] 0.70% 0.70%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Foreign, Land    
Schedule of Investments [Line Items]    
Fair Value [1] $ 169.3 $ 166.6
% of Net Assets [1] 0.70% 0.70%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Georgia    
Schedule of Investments [Line Items]    
Fair Value $ 18.3 $ 18.2
% of Net Assets 0.10% 0.10%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Georgia, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 18.3 $ 18.2
% of Net Assets 0.10% 0.10%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Maryland    
Schedule of Investments [Line Items]    
Fair Value $ 52.5 $ 53.6
% of Net Assets 0.20% 0.30%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Maryland, Office    
Schedule of Investments [Line Items]    
Fair Value $ 35.7 $ 36.5
% of Net Assets 0.10% 0.20%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Maryland, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 16.8 $ 17.1
% of Net Assets 0.10% 0.10%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Massachusetts    
Schedule of Investments [Line Items]    
Fair Value $ 156.2 $ 156.5
% of Net Assets 0.70% 0.70%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Massachusetts, Office    
Schedule of Investments [Line Items]    
Fair Value $ 156.2 $ 156.5
% of Net Assets 0.70% 0.70%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Nevada    
Schedule of Investments [Line Items]    
Fair Value $ 384.6 $ 414.8
% of Net Assets 1.70% 1.80%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Nevada, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 384.6 $ 414.8
% of Net Assets 1.70% 1.80%
Investment, Identifier [Axis]: Real Estate Joint Ventures, New York    
Schedule of Investments [Line Items]    
Fair Value $ 145.8 $ 161.7
% of Net Assets 0.60% 0.70%
Investment, Identifier [Axis]: Real Estate Joint Ventures, New York, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 0.0 $ 46.6
% of Net Assets 0.00% 0.20%
Investment, Identifier [Axis]: Real Estate Joint Ventures, New York, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 66.6 $ 67.3
% of Net Assets 0.30% 0.30%
Investment, Identifier [Axis]: Real Estate Joint Ventures, New York, Office    
Schedule of Investments [Line Items]    
Fair Value $ 48.8 $ 19.5
% of Net Assets 0.20% 0.10%
Investment, Identifier [Axis]: Real Estate Joint Ventures, New York, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 30.4 $ 28.3
% of Net Assets 0.10% 0.10%
Investment, Identifier [Axis]: Real Estate Joint Ventures, North Carolina    
Schedule of Investments [Line Items]    
Fair Value $ 69.8 $ 50.2
% of Net Assets 0.30% 0.20%
Investment, Identifier [Axis]: Real Estate Joint Ventures, North Carolina, Apartments    
Schedule of Investments [Line Items]    
Fair Value $ 1.6 $ 0.0
% of Net Assets 0.00% 0.00%
Investment, Identifier [Axis]: Real Estate Joint Ventures, North Carolina, Land    
Schedule of Investments [Line Items]    
Fair Value $ 23.8 $ 23.6
% of Net Assets 0.10% 0.10%
Investment, Identifier [Axis]: Real Estate Joint Ventures, North Carolina, Office    
Schedule of Investments [Line Items]    
Fair Value $ 43.7 $ 22.8
% of Net Assets 0.20% 0.10%
Investment, Identifier [Axis]: Real Estate Joint Ventures, North Carolina, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 0.7 [2] $ 3.8
% of Net Assets 0.00% 0.00%
Investment, Identifier [Axis]: Real Estate Joint Ventures, South Carolina    
Schedule of Investments [Line Items]    
Fair Value $ 105.1 $ 106.1
% of Net Assets 0.50% 0.50%
Investment, Identifier [Axis]: Real Estate Joint Ventures, South Carolina, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 105.1 $ 106.1
% of Net Assets 0.50% 0.50%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Tennessee    
Schedule of Investments [Line Items]    
Fair Value $ 180.7 $ 182.5
% of Net Assets 0.80% 0.80%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Tennessee, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 180.7 $ 182.5
% of Net Assets 0.80% 0.80%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Texas    
Schedule of Investments [Line Items]    
Fair Value $ 366.6 $ 355.0
% of Net Assets 1.60% 1.50%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Texas, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 53.4 $ 49.1
% of Net Assets 0.20% 0.20%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Texas, Office    
Schedule of Investments [Line Items]    
Fair Value $ 313.2 $ 305.9
% of Net Assets 1.40% 1.30%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Various    
Schedule of Investments [Line Items]    
Fair Value [3] $ 2,415.6 $ 2,367.4
% of Net Assets [3] 10.50% 10.40%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Various, Apartment    
Schedule of Investments [Line Items]    
Fair Value [3] $ 667.5 $ 660.0
% of Net Assets [3] 2.90% 2.90%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Various, Office    
Schedule of Investments [Line Items]    
Fair Value [3] $ 526.1 $ 500.9
% of Net Assets [3] 2.30% 2.20%
Investment, Identifier [Axis]: Real Estate Joint Ventures, Various, Storage    
Schedule of Investments [Line Items]    
Fair Value [3] $ 1,222.0 $ 1,206.5
% of Net Assets [3] 5.30% 5.30%
Investment, Identifier [Axis]: Real Estate Properties, Alabama    
Schedule of Investments [Line Items]    
Fair Value $ 25.6 $ 25.6
% of Net Assets 0.10% 0.10%
Investment, Identifier [Axis]: Real Estate Properties, Alabama, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 25.6 $ 25.6
% of Net Assets 0.10% 0.10%
Investment, Identifier [Axis]: Real Estate Properties, Arizona    
Schedule of Investments [Line Items]    
Fair Value $ 118.2 $ 90.6
% of Net Assets 0.50% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Arizona, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 118.2 $ 90.6
% of Net Assets 0.50% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, California    
Schedule of Investments [Line Items]    
Fair Value $ 4,500.4 $ 4,578.7
% of Net Assets 19.60% 20.10%
Investment, Identifier [Axis]: Real Estate Properties, California, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 940.8 $ 1,002.0
% of Net Assets 4.10% 4.40%
Investment, Identifier [Axis]: Real Estate Properties, California, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 3,006.0 $ 3,032.3
% of Net Assets 13.10% 13.30%
Investment, Identifier [Axis]: Real Estate Properties, California, Office    
Schedule of Investments [Line Items]    
Fair Value $ 57.1 $ 56.5
% of Net Assets 0.20% 0.30%
Investment, Identifier [Axis]: Real Estate Properties, California, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 496.5 $ 487.9
% of Net Assets 2.20% 2.10%
Investment, Identifier [Axis]: Real Estate Properties, Colorado    
Schedule of Investments [Line Items]    
Fair Value $ 82.5 $ 86.4
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Colorado, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 43.6 $ 43.9
% of Net Assets 0.20% 0.20%
Investment, Identifier [Axis]: Real Estate Properties, Colorado, Office    
Schedule of Investments [Line Items]    
Fair Value $ 38.9 $ 42.5
% of Net Assets 0.20% 0.20%
Investment, Identifier [Axis]: Real Estate Properties, Connecticut    
Schedule of Investments [Line Items]    
Fair Value $ 23.7 $ 25.1
% of Net Assets 0.10% 0.10%
Investment, Identifier [Axis]: Real Estate Properties, Connecticut, Office    
Schedule of Investments [Line Items]    
Fair Value $ 23.7 $ 25.1
% of Net Assets 0.10% 0.10%
Investment, Identifier [Axis]: Real Estate Properties, Florida    
Schedule of Investments [Line Items]    
Fair Value $ 1,909.9 $ 1,868.9
% of Net Assets 8.30% 8.20%
Investment, Identifier [Axis]: Real Estate Properties, Florida, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 972.0 $ 955.4
% of Net Assets 4.20% 4.20%
Investment, Identifier [Axis]: Real Estate Properties, Florida, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 861.2 $ 837.3
% of Net Assets 3.80% 3.70%
Investment, Identifier [Axis]: Real Estate Properties, Florida, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 76.7 $ 76.2
% of Net Assets 0.30% 0.30%
Investment, Identifier [Axis]: Real Estate Properties, Georgia    
Schedule of Investments [Line Items]    
Fair Value $ 1,043.9 $ 811.7
% of Net Assets 4.60% 3.60%
Investment, Identifier [Axis]: Real Estate Properties, Georgia, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 369.7 $ 376.8
% of Net Assets 1.60% 1.70%
Investment, Identifier [Axis]: Real Estate Properties, Georgia, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 539.4 $ 299.5
% of Net Assets 2.40% 1.30%
Investment, Identifier [Axis]: Real Estate Properties, Georgia, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 134.8 $ 135.4
% of Net Assets 0.60% 0.60%
Investment, Identifier [Axis]: Real Estate Properties, Illinois    
Schedule of Investments [Line Items]    
Fair Value $ 673.6 $ 657.8
% of Net Assets 2.90% 2.90%
Investment, Identifier [Axis]: Real Estate Properties, Illinois, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 214.4 $ 201.4
% of Net Assets 0.90% 0.90%
Investment, Identifier [Axis]: Real Estate Properties, Illinois, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 215.1 $ 214.1
% of Net Assets 0.90% 0.90%
Investment, Identifier [Axis]: Real Estate Properties, Illinois, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 244.1 $ 242.3
% of Net Assets 1.10% 1.10%
Investment, Identifier [Axis]: Real Estate Properties, Indiana    
Schedule of Investments [Line Items]    
Fair Value $ 98.5 $ 98.2
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Indiana, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 98.5 $ 98.2
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Maryland    
Schedule of Investments [Line Items]    
Fair Value $ 218.4 $ 219.1
% of Net Assets 1.00% 1.00%
Investment, Identifier [Axis]: Real Estate Properties, Maryland, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 72.7 $ 76.2
% of Net Assets 0.30% 0.30%
Investment, Identifier [Axis]: Real Estate Properties, Maryland, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 92.6 $ 87.3
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Maryland, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 53.1 $ 55.6
% of Net Assets 0.30% 0.30%
Investment, Identifier [Axis]: Real Estate Properties, Massachusetts    
Schedule of Investments [Line Items]    
Fair Value $ 415.1 $ 483.2
% of Net Assets 1.80% 2.10%
Investment, Identifier [Axis]: Real Estate Properties, Massachusetts, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 165.7 $ 167.0
% of Net Assets 0.70% 0.70%
Investment, Identifier [Axis]: Real Estate Properties, Massachusetts, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 132.5 $ 137.8
% of Net Assets 0.60% 0.60%
Investment, Identifier [Axis]: Real Estate Properties, Massachusetts, Office    
Schedule of Investments [Line Items]    
Fair Value $ 28.4 $ 88.7
% of Net Assets 0.10% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Massachusetts, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 88.5 $ 89.7
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Minnesota    
Schedule of Investments [Line Items]    
Fair Value $ 135.1 $ 134.2
% of Net Assets 0.60% 0.60%
Investment, Identifier [Axis]: Real Estate Properties, Minnesota, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 135.1 $ 134.2
% of Net Assets 0.60% 0.60%
Investment, Identifier [Axis]: Real Estate Properties, Nevada    
Schedule of Investments [Line Items]    
Fair Value $ 91.6 $ 92.4
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Nevada, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 91.6 $ 92.4
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, New Jersey    
Schedule of Investments [Line Items]    
Fair Value $ 491.4 $ 488.9
% of Net Assets 2.10% 2.10%
Investment, Identifier [Axis]: Real Estate Properties, New Jersey, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 369.8 $ 373.2
% of Net Assets 1.60% 1.60%
Investment, Identifier [Axis]: Real Estate Properties, New Jersey, Land    
Schedule of Investments [Line Items]    
Fair Value $ 33.3 $ 28.7
% of Net Assets 0.10% 0.10%
Investment, Identifier [Axis]: Real Estate Properties, New Jersey, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 88.3 $ 87.0
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, New York    
Schedule of Investments [Line Items]    
Fair Value $ 538.1 $ 516.1
% of Net Assets 2.30% 2.20%
Investment, Identifier [Axis]: Real Estate Properties, New York, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 253.1 $ 256.4
% of Net Assets 1.10% 1.10%
Investment, Identifier [Axis]: Real Estate Properties, New York, Office    
Schedule of Investments [Line Items]    
Fair Value $ 285.0 $ 259.7
% of Net Assets 1.20% 1.10%
Investment, Identifier [Axis]: Real Estate Properties, North Carolina    
Schedule of Investments [Line Items]    
Fair Value $ 234.2 $ 287.4
% of Net Assets 1.00% 1.30%
Investment, Identifier [Axis]: Real Estate Properties, North Carolina, Apartments    
Schedule of Investments [Line Items]    
Fair Value $ 77.2 $ 78.2
% of Net Assets 0.30% 0.30%
Investment, Identifier [Axis]: Real Estate Properties, North Carolina, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 108.1 $ 102.7
% of Net Assets 0.50% 0.50%
Investment, Identifier [Axis]: Real Estate Properties, North Carolina, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 48.9 $ 106.5
% of Net Assets 0.20% 0.50%
Investment, Identifier [Axis]: Real Estate Properties, Oregon    
Schedule of Investments [Line Items]    
Fair Value $ 58.1 $ 80.9
% of Net Assets 0.30% 0.30%
Investment, Identifier [Axis]: Real Estate Properties, Oregon, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 30.7 $ 29.9
% of Net Assets 0.20% 0.10%
Investment, Identifier [Axis]: Real Estate Properties, Oregon, Office    
Schedule of Investments [Line Items]    
Fair Value $ 27.4 $ 51.0
% of Net Assets 0.10% 0.20%
Investment, Identifier [Axis]: Real Estate Properties, Pennsylvania    
Schedule of Investments [Line Items]    
Fair Value $ 55.5 $ 59.4
% of Net Assets 0.20% 0.30%
Investment, Identifier [Axis]: Real Estate Properties, Pennsylvania, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 55.5 $ 59.4
% of Net Assets 0.20% 0.30%
Investment, Identifier [Axis]: Real Estate Properties, South Carolina    
Schedule of Investments [Line Items]    
Fair Value $ 90.0 $ 87.7
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, South Carolina, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 90.0 $ 87.7
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Tennessee    
Schedule of Investments [Line Items]    
Fair Value $ 222.6 $ 205.9
% of Net Assets 1.00% 0.90%
Investment, Identifier [Axis]: Real Estate Properties, Tennessee, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 46.0 $ 43.2
% of Net Assets 0.20% 0.20%
Investment, Identifier [Axis]: Real Estate Properties, Tennessee, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 80.9 $ 77.1
% of Net Assets 0.40% 0.30%
Investment, Identifier [Axis]: Real Estate Properties, Tennessee, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 95.7 $ 85.6
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Texas    
Schedule of Investments [Line Items]    
Fair Value $ 2,435.9 $ 2,500.0
% of Net Assets 10.60% 11.00%
Investment, Identifier [Axis]: Real Estate Properties, Texas, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 549.8 $ 513.8
% of Net Assets 2.50% 2.30%
Investment, Identifier [Axis]: Real Estate Properties, Texas, Hotel    
Schedule of Investments [Line Items]    
Fair Value $ 95.5 $ 96.0
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Texas, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 1,019.7 $ 1,114.0
% of Net Assets 4.40% 4.90%
Investment, Identifier [Axis]: Real Estate Properties, Texas, Office    
Schedule of Investments [Line Items]    
Fair Value $ 669.8 $ 676.2
% of Net Assets 2.90% 3.00%
Investment, Identifier [Axis]: Real Estate Properties, Texas, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 101.1 $ 100.0
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Utah    
Schedule of Investments [Line Items]    
Fair Value $ 81.9 $ 82.2
% of Net Assets 0.40% 0.40%
Investment, Identifier [Axis]: Real Estate Properties, Utah, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 36.7 $ 36.7
% of Net Assets 0.20% 0.20%
Investment, Identifier [Axis]: Real Estate Properties, Utah, Office    
Schedule of Investments [Line Items]    
Fair Value $ 45.2 $ 45.5
% of Net Assets 0.20% 0.20%
Investment, Identifier [Axis]: Real Estate Properties, Virginia    
Schedule of Investments [Line Items]    
Fair Value $ 616.3 $ 624.0
% of Net Assets 2.70% 2.70%
Investment, Identifier [Axis]: Real Estate Properties, Virginia, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 399.5 $ 409.1
% of Net Assets 1.70% 1.80%
Investment, Identifier [Axis]: Real Estate Properties, Virginia, Office    
Schedule of Investments [Line Items]    
Fair Value $ 85.2 $ 79.4
% of Net Assets 0.40% 0.30%
Investment, Identifier [Axis]: Real Estate Properties, Virginia, Retail    
Schedule of Investments [Line Items]    
Fair Value $ 131.6 $ 135.5
% of Net Assets 0.60% 0.60%
Investment, Identifier [Axis]: Real Estate Properties, Washington    
Schedule of Investments [Line Items]    
Fair Value $ 942.5 $ 944.1
% of Net Assets 4.10% 4.20%
Investment, Identifier [Axis]: Real Estate Properties, Washington D.C.    
Schedule of Investments [Line Items]    
Fair Value $ 875.2 $ 926.9
% of Net Assets 3.80% 4.10%
Investment, Identifier [Axis]: Real Estate Properties, Washington D.C., Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 267.2 $ 286.7
% of Net Assets 1.20% 1.30%
Investment, Identifier [Axis]: Real Estate Properties, Washington D.C., Office    
Schedule of Investments [Line Items]    
Fair Value $ 608.0 $ 640.2
% of Net Assets 2.60% 2.80%
Investment, Identifier [Axis]: Real Estate Properties, Washington, Apartment    
Schedule of Investments [Line Items]    
Fair Value $ 290.9 $ 285.7
% of Net Assets 1.30% 1.30%
Investment, Identifier [Axis]: Real Estate Properties, Washington, Industrial    
Schedule of Investments [Line Items]    
Fair Value $ 651.6 $ 658.4
% of Net Assets 2.80% 2.90%
Investment, Identifier [Axis]: Reverse repurchase agreements    
Schedule of Investments [Line Items]    
Fair Value $ 417.2 $ 208.2
% of Net Assets 1.80% 0.90%
Investment, Identifier [Axis]: U.S. government agency notes    
Schedule of Investments [Line Items]    
Fair Value $ 763.3 $ 621.1
% of Net Assets 3.30% 2.70%
Investment, Identifier [Axis]: U.S. treasury securities    
Schedule of Investments [Line Items]    
Fair Value $ 475.3 $ 899.4
% of Net Assets 2.10% 3.90%
Real Estate Properties    
Schedule of Investments [Line Items]    
Fair Value $ 15,978.2 $ 15,975.4
% of Net Assets 69.60% 70.20%
Total investments at cost $ 13,026.0 $ 12,973.4
Real Estate Joint Ventures    
Schedule of Investments [Line Items]    
Fair Value $ 5,206.6 $ 5,098.8
% of Net Assets 22.70% 22.40%
Total investments at cost $ 5,109.8 $ 5,115.5
[1] Property is located outside of the United States.
[2] Represents residual equity value of the joint venture investment after property disposition.
[3] Properties within these investments are located throughout the United States.