Investments - Schedule of Principal Geographic Distribution of Municipal Bond Issuers Exceeding 5% of the Portfolio (Details)	Dec. 31, 2024	Dec. 31, 2023
Texas
Municipal Bonds
Percentage of municipal bond portfolio carrying value (as a percent)	12.80%	12.80%
California
Municipal Bonds
Percentage of municipal bond portfolio carrying value (as a percent)	6.80%	7.70%
Florida
Municipal Bonds
Percentage of municipal bond portfolio carrying value (as a percent)	6.50%	4.80%
Washington
Municipal Bonds
Percentage of municipal bond portfolio carrying value (as a percent)	6.50%	3.10%
Illinois
Municipal Bonds
Percentage of municipal bond portfolio carrying value (as a percent)	6.10%	5.40%
New York
Municipal Bonds
Percentage of municipal bond portfolio carrying value (as a percent)	6.00%	6.30%
Pennsylvania
Municipal Bonds
Percentage of municipal bond portfolio carrying value (as a percent)	4.00%	5.40%