CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
INVESTMENT INCOME:
PIK interest income	$ 166.0	$ 138.0	$ 164.0
Total investment income	2,614.0	2,096.0	1,820.0
EXPENSES:
Interest and credit facility fees	582.0	455.0	372.0
Base management fees	323.0	305.0	253.0
Income based fees	328.0	252.0	225.0
Capital gains incentive fees	53.0	(101.0)	161.0
Administrative and other fees	13.0	11.0	15.0
Other general and administrative	29.0	27.0	24.0
Total expenses	1,328.0	949.0	1,050.0
NET INVESTMENT INCOME BEFORE INCOME TAXES	1,286.0	1,147.0	770.0
Income tax expense, including excise tax	20.0	55.0	29.0
NET INVESTMENT INCOME	1,266.0	1,092.0	741.0
REALIZED AND UNREALIZED GAINS (LOSSES) ON INVESTMENTS, FOREIGN CURRENCY AND OTHER TRANSACTIONS:
Foreign currency and other transactions	(24.0)	57.0	25.0
Net realized (losses) gains	(179.0)	81.0	283.0
Foreign currency and other transactions	6.0	(12.0)	(16.0)
Net unrealized gains (losses)	435.0	(525.0)	586.0
Net realized and unrealized gains (losses) on investments, foreign currency and other transactions	256.0	(444.0)	869.0
REALIZED LOSS ON EXTINGUISHMENT OF DEBT	0.0	(48.0)	(43.0)
NET INCREASE IN STOCKHOLDERS’ EQUITY RESULTING FROM OPERATIONS	$ 1,522.0	$ 600.0	$ 1,567.0
NET INCOME PER COMMON SHARE (see Note 10)
Basic (in usd per share)	$ 2.75	$ 1.21	$ 3.51
Diluted (in usd per share)	$ 2.68	$ 1.19	$ 3.51
WEIGHTED AVERAGE SHARES OF COMMON STOCK OUTSTANDING (see Note 10)
Basic (in shares)	554	498	446
Diluted (in shares)	575	518	446
Non-controlled/non-affiliate company investments
INVESTMENT INCOME:
Interest income (excluding payment-in-kind (“PIK”) interest income)	$ 1,564.0	$ 1,141.0	$ 911.0
PIK interest income	143.0	121.0	133.0
Capital structuring service fees	83.0	133.0	285.0
Dividend income	242.0	194.0	122.0
Other income	53.0	43.0	40.0
Total investment income	2,085.0	1,632.0	1,491.0
REALIZED AND UNREALIZED GAINS (LOSSES) ON INVESTMENTS, FOREIGN CURRENCY AND OTHER TRANSACTIONS:
Net realized gains (losses):	(146.0)	56.0	129.0
Net unrealized gains (losses):	379.0	(585.0)	556.0
Non-controlled affiliate company investments
INVESTMENT INCOME:
Interest income (excluding payment-in-kind (“PIK”) interest income)	12.0	8.0	7.0
PIK interest income	5.0	5.0	4.0
Capital structuring service fees	0.0
Dividend income	7.4	2.0	0.0
Other income	0.1	0.0	1.0
Total investment income	24.0	15.0	12.0
REALIZED AND UNREALIZED GAINS (LOSSES) ON INVESTMENTS, FOREIGN CURRENCY AND OTHER TRANSACTIONS:
Net realized gains (losses):	(10.2)	6.0	68.0
Net unrealized gains (losses):	34.3	71.0	(16.0)
Controlled affiliate company investments
INVESTMENT INCOME:
Interest income (excluding payment-in-kind (“PIK”) interest income)	220.0	183.0	164.0
PIK interest income	18.0	12.0	28.0
Capital structuring service fees	8.8	20.0	21.0
Dividend income	252.2	228.2	100.0
Other income	5.7	6.0	4.0
Total investment income	505.0	449.0	317.0
REALIZED AND UNREALIZED GAINS (LOSSES) ON INVESTMENTS, FOREIGN CURRENCY AND OTHER TRANSACTIONS:
Net realized gains (losses):	0.6	(37.5)	61.0
Net unrealized gains (losses):	$ 15.6	$ 1.0	$ 62.0