Consolidated Statements of Operations - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024		Dec. 31, 2023		Dec. 31, 2022
Investment income
Paid-in-kind interest income		$ 203.0		$ 144.0		$ 120.0
Total investment income		1,721.0		1,830.0		1,635.0
Operating expenses
Management fees		216.0		226.0		245.0
Subordinated income incentive fees	[1]	167.0		181.0		159.0
Administrative services expenses		10.0		12.0		15.0
Accounting and administrative fees		4.0		4.0		5.0
Interest expense	[2]	465.0		467.0		365.0
Other general and administrative expenses		23.0		26.0		22.0
Total operating expenses		885.0		916.0		811.0
Incentive fee waiver	[1]	0.0		0.0		(60.0)
Net expenses		885.0		916.0		751.0
Net investment income before taxes		836.0		914.0		884.0
Excise taxes		23.0		22.0		19.0
Net investment income		813.0		892.0		865.0
Realized and unrealized gain/loss
Net realized gain (loss) on investments:		(486.0)		(343.0)		149.0
Net realized gain (loss) on foreign currency forward contracts		19.0		8.0		10.0
Net change in unrealized appreciation (depreciation) on investments:		217.0		166.0		(981.0)
Net change in unrealized appreciation (depreciation) on foreign currency forward contracts		(7.0)		(15.0)		16.0
Net change in unrealized gain (loss) on foreign currency		38.0		(21.0)		15.0
Total net realized and unrealized gain (loss)		(228.0)		(193.0)		(768.0)
Provision for taxes on realized and unrealized gains on investments		0.0		(3.0)		(5.0)
Net increase (decrease) in net assets resulting from operations		$ 585.0		$ 696.0		$ 92.0
Per share information—basic and diluted
Net increase (decrease) in net assets resulting from operations (Earnings per Share) - basic (in dollars per share)		$ 2.09		$ 2.48		$ 0.32
Net increase (decrease) in net assets resulting from operations (Earnings per Share) - diluted (in dollars per share)		$ 2.09		$ 2.48		$ 0.32
Weighted average shares outstanding - basic (in shares)		280,066,433		280,276,768		283,508,494
Weighted average shares outstanding - diluted (in shares)		280,066,433		280,276,768		283,508,494
Non-controlled/unaffiliated
Investment income
Interest income		$ 1,059.0		$ 1,183.0		$ 1,020.0
Paid-in-kind interest income		67.0		108.0		72.0
Fee income		53.0		30.0		74.0
Dividend and other income		26.0		14.0		50.0
Realized and unrealized gain/loss
Net realized gain (loss) on investments:		(448.0)		(147.0)		136.0
Net realized gain (loss) on foreign currency		(9.0)		12.0		23.0
Net change in unrealized appreciation (depreciation) on investments:		255.0		30.0		(679.0)
Non-controlled/affiliated
Investment income
Interest income		42.0		25.0		28.0
Paid-in-kind interest income		49.6	[3]	39.4	[4]	48.0
Fee income		1.1	[3]	1.3	[4]	6.0
Dividend and other income		15.5	[3]	27.9	[4]	7.0
Realized and unrealized gain/loss
Net realized gain (loss) on investments:		(60.7)		(21.2)		84.0
Net change in unrealized appreciation (depreciation) on investments:		134.4		9.4		(131.0)
Controlled/affiliated
Investment income
Interest income		71.0		87.0		58.0
Paid-in-kind interest income		93.5	[5]	44.5	[6]	43.0
Fee income		9.3	[5]	3.8	[6]	0.0
Dividend and other income		232.5	[5]	266.0	[6]	229.0
Realized and unrealized gain/loss
Net realized gain (loss) on investments:		23.2		(174.8)		(71.0)
Net change in unrealized appreciation (depreciation) on investments:		$ (171.6)		$ 126.7		$ (171.0)

[1] See Note 2 and 4 for a discussion of the methodology employed by the Company in calculating the subordinated income incentive fees.

[2] See Note 9 for a discussion of the Company’s financing arrangements.

[3] Interest, PIK, fee and dividend and other income presented for the full year ended December 31, 2024.

[4] Interest, PIK, fee and dividend and other income presented for the full year ended December 31, 2023.

[5] Interest, PIK, fee and dividend and other income presented for the full year ended December 31, 2024.

[6] Interest, PIK, fee and dividend and other income presented for the full year ended December 31, 2023.