Investments - Available for Sale Securities (Details) - USD ($) $ in Thousands		Mar. 31, 2025		Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Less: loaned securities		$ 154,891		$ 139,121
Total fixed-maturities, available for sale, Amortized Cost		5,479,486		5,511,501
Total fixed-maturities available for sale, Fair Value		5,112,192		5,074,920
Total fixed-maturities available for sale
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		5,616,718		5,648,583
Total fixed-maturities, available for sale, Amortized Cost		5,479,486		5,511,501	[1]
Gross Unrealized Gains		23,898		16,565
Gross Unrealized Losses	[2]	(397,486)		(460,376)
Fair Value		5,243,130		5,204,772
Total fixed-maturities available for sale, Fair Value		5,112,192		5,074,920	[1]
U.S. government and agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		171,718		160,509
Gross Unrealized Gains		8		0
Gross Unrealized Losses		(28,490)		(32,177)
Fair Value		143,236		128,332
State and municipal obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		157,430		167,114
Gross Unrealized Gains		269		40
Gross Unrealized Losses		(15,821)		(18,263)
Fair Value		141,878		148,891
Corporate bonds and notes
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		2,829,292		2,878,705
Gross Unrealized Gains		10,268		5,261
Gross Unrealized Losses		(245,503)		(277,535)
Fair Value		2,594,057		2,606,431
RMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		1,080,716		1,104,721
Gross Unrealized Gains		8,457		6,965
Gross Unrealized Losses		(82,848)		(100,056)
Fair Value		1,006,325		1,011,630
CMBS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		415,327		438,139
Gross Unrealized Gains		50		51
Gross Unrealized Losses		(20,936)		(26,191)
Fair Value		394,441		411,999
CLO
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		396,203		411,328
Gross Unrealized Gains		273		983
Gross Unrealized Losses		(717)		(849)
Fair Value		395,759		411,462
Other ABS
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		520,648		442,620
Gross Unrealized Gains		2,970		1,556
Gross Unrealized Losses		(3,171)		(5,305)
Fair Value		520,447		438,871
Mortgage insurance-linked notes
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	[3]	45,384		45,447
Gross Unrealized Gains	[3]	1,603		1,709
Gross Unrealized Losses	[3]	0		0
Fair Value	[3]	46,987		47,156
Loaned securities, amortized cost | Total fixed-maturities available for sale
Debt Securities, Available-for-sale [Line Items]
Less: loaned securities		137,232	[1]	137,082
Loaned securities, fair value | Total fixed-maturities available for sale
Debt Securities, Available-for-sale [Line Items]
Less: loaned securities		$ 130,938	[1]	$ 129,852

[1] Included in other assets on our condensed consolidated balance sheets. See “Loaned Securities” below for a discussion of our securities lending agreements.

[2] See “Gross Unrealized Losses and Related Fair Value of Available for Sale Securities” below for additional details.

[3] Includes mortgage insurance-linked notes purchased by Radian Group in connection with the XOL Program. See Note 8 for more information.