Financial Highlights - Summary of Financial Highlights for One Share Common Stock Outstanding (Parenthetical) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Investment Company, Financial Highlights [Line Items]
Ratio of net expenses to average net asset, excluding waiver	17.00%	11.08%	11.19%			11.33%	9.42%	9.43%	9.33%	7.88%
Management and incentive fees waived				$ 0	$ 0
Shares of common stock	87,829,499	81,389,287
ICC Capital Corp.
Investment Company, Financial Highlights [Line Items]
Shares of common stock										0