CONSOLIDATED STATEMENT OF STOCKHOLDERS’ EQUITY - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Capital in Excess of Par Value	Capital in Excess of Par Value Cumulative Effect, Period of Adoption, Adjustment	Accumulated Undistributed (Overdistributed) Earnings	Accumulated Undistributed (Overdistributed) Earnings Cumulative Effect, Period of Adoption, Adjustment
Beginning balance (in shares) at Dec. 31, 2021			468,000,000
Beginning balance at Dec. 31, 2021	$ 8,868.0	$ (2.0)	$ 0.0	$ 8,553.0	$ (4.0)	$ 315.0	$ 2.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of offering and underwriting costs (in shares)			50,000,000
Issuance of common stock, net of offering and underwriting costs	$ 1,001.0		$ 1.0	1,000.0
Shares issued in connection with dividend reinvestment plan (in shares)	1,500,000		1,000,000
Shares issued in connection with dividend reinvestment plan	$ 29.0			29.0
Net investment income	1,092.0					1,092.0
Net realized gains (losses) on investments, foreign currency, extinguishment of debt and other transactions	33.0					33.0
Net unrealized (losses) gains on investments, foreign currency and other transactions	(525.0)					(525.0)
Dividends declared and payable	(941.0)					(941.0)
Tax reclassification of stockholders’ equity in accordance with GAAP	0.0			(22.0)		22.0
Ending balance (in shares) at Dec. 31, 2022			519,000,000
Ending balance at Dec. 31, 2022	9,555.0		$ 1.0	9,556.0		(2.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of offering and underwriting costs (in shares)			61,000,000
Issuance of common stock, net of offering and underwriting costs	$ 1,155.0			1,155.0
Shares issued in connection with dividend reinvestment plan (in shares)	2,500,000		2,000,000
Shares issued in connection with dividend reinvestment plan	$ 47.0			47.0
Net investment income	1,266.0					1,266.0
Net realized gains (losses) on investments, foreign currency, extinguishment of debt and other transactions	(179.0)					(179.0)
Net unrealized (losses) gains on investments, foreign currency and other transactions	435.0					435.0
Dividends declared and payable	(1,078.0)					(1,078.0)
Tax reclassification of stockholders’ equity in accordance with GAAP	$ 0.0			(20.0)		20.0
Ending balance (in shares) at Dec. 31, 2023	582,000,000		582,000,000
Ending balance at Dec. 31, 2023	$ 11,201.0		$ 1.0	10,738.0		462.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of offering and underwriting costs (in shares)			66,000,000
Issuance of common stock, net of offering and underwriting costs	$ 1,364.0			1,364.0
Shares issued in connection with dividend reinvestment plan (in shares)	3,800,000		4,000,000
Shares issued in connection with dividend reinvestment plan	$ 80.0			80.0
Net investment income	1,403.0					1,403.0
Net realized gains (losses) on investments, foreign currency, extinguishment of debt and other transactions	(69.0)					(69.0)
Net unrealized (losses) gains on investments, foreign currency and other transactions	188.0					188.0
Conversion of 2024 Convertible Notes (in shares)			20,000,000
Conversion of 2024 Convertible Notes	407.0			407.0
Dividends declared and payable	(1,219.0)					(1,219.0)
Tax reclassification of stockholders’ equity in accordance with GAAP	$ 0.0			(87.0)		87.0
Ending balance (in shares) at Dec. 31, 2024	672,000,000		672,000,000
Ending balance at Dec. 31, 2024	$ 13,355.0		$ 1.0	$ 12,502.0		$ 852.0