Investments - Geographic Investment (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2026	Dec. 31, 2025
Schedule of Investments [Line Items]
Cost	$ 13,250,120	$ 14,387,967
Fair Value	$ 12,946,234	$ 14,207,294
Fair Value as % of Net Assets	220.00%	227.50%
Investment Owned, At Fair Value \| Investment Type Concentration Risk
Schedule of Investments [Line Items]
Concentration Risk, Percentage	100.00%	100.00%
United States
Schedule of Investments [Line Items]
Cost	$ 11,370,932	$ 12,488,551
Fair Value	$ 11,087,929	$ 12,259,789
Fair Value as % of Net Assets	188.50%	196.30%
United States \| Investment Owned, At Fair Value \| Investment Type Concentration Risk
Schedule of Investments [Line Items]
Concentration Risk, Percentage	85.60%	86.30%
Europe
Schedule of Investments [Line Items]
Cost	$ 981,163	$ 1,601,031
Fair Value	$ 958,843	$ 1,645,999
Fair Value as % of Net Assets	16.30%	26.30%
Europe \| Investment Owned, At Fair Value \| Investment Type Concentration Risk
Schedule of Investments [Line Items]
Concentration Risk, Percentage	7.40%	11.60%
United Kingdom
Schedule of Investments [Line Items]
Cost	$ 767,264
Fair Value	$ 772,756
Fair Value as % of Net Assets	13.10%
United Kingdom \| Investment Owned, At Fair Value \| Investment Type Concentration Risk
Schedule of Investments [Line Items]
Concentration Risk, Percentage	6.00%
Canada
Schedule of Investments [Line Items]
Cost	$ 68,226	$ 138,265
Fair Value	$ 65,498	$ 140,444
Fair Value as % of Net Assets	1.10%	2.30%
Canada \| Investment Owned, At Fair Value \| Investment Type Concentration Risk
Schedule of Investments [Line Items]
Concentration Risk, Percentage	0.50%	1.00%
Australia
Schedule of Investments [Line Items]
Cost	$ 50,102
Fair Value	$ 48,451
Fair Value as % of Net Assets	0.80%
Australia \| Investment Owned, At Fair Value \| Investment Type Concentration Risk
Schedule of Investments [Line Items]
Concentration Risk, Percentage	0.40%
Asia
Schedule of Investments [Line Items]
Cost	$ 11,974	$ 11,900
Fair Value	$ 12,150	$ 12,096
Fair Value as % of Net Assets	0.20%	0.20%
Asia \| Investment Owned, At Fair Value \| Investment Type Concentration Risk
Schedule of Investments [Line Items]
Concentration Risk, Percentage	0.10%	0.10%
Bermuda/Cayman Islands
Schedule of Investments [Line Items]
Cost	$ 459	$ 148,220
Fair Value	$ 607	$ 148,966
Fair Value as % of Net Assets	0.00%	2.40%
Bermuda/Cayman Islands \| Investment Owned, At Fair Value \| Investment Type Concentration Risk
Schedule of Investments [Line Items]
Concentration Risk, Percentage	0.00%	1.00%