Income Taxes - Schedule of Income Tax Expense (Benefit) (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Income Tax Disclosure [Abstract]
U.S. federal and state corporate-level income tax expense/(benefit)	$ 3,216,000	$ 3,092,000	$ 6,375,000	$ 9,124,000
U.S. federal excise tax expense	1,797,000	1,750,000	4,557,000	4,750,000
Federal and state income tax expense/(benefit) for taxable subsidiaries	$ 1,419,000	$ 1,342,000	$ 1,818,000	$ 4,374,000

Amount of tax expense (benefit) on investment income classified as operating. Excludes realized and unrealized gain (loss) on investment.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-07(5))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479134/946-220-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section 45
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479105/946-220-45-4

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478297/946-220-50-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 946
-SubTopic 220
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479105/946-220-45-3

Name:	us-gaap_InvestmentIncomeOperatingTaxExpenseBenefit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration