Financial Highlights (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Per share data:
Net asset value at beginning of period (in dollars per share)	$ 10.24	$ 10.13	$ 10.10	$ 9.94	$ 10.00	$ 10.00
Net investment income (in dollars per share)	1.20	1.21	0.90	0.76	0.85	0.57
Net gain (loss) (in dollars per share)	0.07	(0.02)	(0.07)	0.44	(0.10)	0.22
Net increase (decrease) in net assets resulting from operations (in dollars per share)	1.27	1.19	0.83	1.20	0.75	0.79
Stockholder distributions declared (in dollars per share)	(1.16)	(1.11)	(0.82)	(0.96)	(0.60)	(0.77)
Stockholder distributions - long-term capital gains (in dollars per share)	0	0	0	(0.02)	0	0
Stockholder distributions - return of capital (in dollars per share)	0	0	0	(0.02)	0	0
Other (in dollars per share)	0.02	0.03	0.02	(0.04)	(0.21)	(0.02)
Net asset value at end of period (in dollars per share)	$ 10.37	$ 10.24	$ 10.13	$ 10.10	$ 9.94	$ 10.00
Total return based on average net asset value	13.08%	12.53%	8.68%	12.26%	5.84%	7.92%
Ratio/Supplemental data:
Net assets at end of period	$ 2,059,727	$ 1,302,667	$ 754,916	$ 369,448	$ 137,513	$ 68,745
Shares outstanding at end of period (in shares)	198,704,495	127,232,772	74,533,202	36,565,162	13,827,515	6,874,532
Portfolio turnover	20.67%	9.66%	14.38%	22.52%	18.55%	10.43%
Ratio of net investment income to average net assets	24.10%	22.50%	16.08%	13.31%	12.86%	12.53%
Ratio of expenses to average net assets	12.62%	10.89%	7.34%	5.97%	4.02%	5.16%
Ratio of expenses to average net assets without waivers	12.62%	10.89%	7.90%	7.57%	6.82%	8.68%
Ratio of net investment income to average net assets	11.49%	11.61%	8.18%	5.74%	6.04%	3.85%
Ratio of net investment income to average net assets with waivers	11.49%	11.61%	8.74%	7.34%	8.84%	7.37%