Consolidated Statements of Assets And Liabilities - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Investments at fair value:
Cash	$ 19,352	$ 10,743
Cash equivalents (cost: $425,220 and $417,590, respectively)	425,082	417,590
Dividends receivable	10,754	11,192
Interest receivable	10,507	9,706
Receivable for investments sold	1,188	1,124
Prepaid expenses and other assets	855	664
Total assets	2,556,199	2,537,695
Liabilities
Debt ($1,122,200 and $1,093,200 face amounts, respectively, reported net of unamortized debt issuance costs of $6,678 and $7,202, respectively. See notes 6 and 7)	1,115,522	1,085,998
Payable for investments and cash equivalents purchased	425,220	417,611
Distributions payable	7,456	7,481
Management fee payable (see note 3)	7,706	7,964
Performance-based incentive fee payable (see note 3)	5,399	5,422
Interest payable (see note 7)	6,527	7,943
Administrative services payable (see note 3)	749	1,488
Other liabilities and accrued expenses	3,442	4,057
Total liabilities	1,572,021	1,537,964
Commitments and contingencies (see note 10)
Net Assets
Common stock, par value $0.01 per share, 200,000,000 and 200,000,000 common shares authorized, respectively, and 54,554,634 and 54,555,380 shares issued and outstanding, respectively	546	546
Paid-in capital in excess of par	1,162,559	1,162,569
Accumulated distributable net loss	(178,927)	(163,384)
Total net assets	$ 984,178	$ 999,731
Net Asset Value Per Share	$ 18.04	$ 18.33
Companies less than 5% owned [Member]
Investments at fair value:
Investments at fair value:	$ 1,295,133	$ 1,289,082
Companies more than 25% owned [Member]
Investments at fair value:
Investments at fair value:	$ 793,328	$ 797,594