Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value by Hierarchy Level (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	$ 148,098	$ 203,693
Other invested assets—at fair value	7,422	8,625
Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	6,586,355	6,084,225
Derivative assets	4,688	1,913
Mortgage servicing rights	1,561
Total assets at fair value	6,740,702	6,289,831
Derivative Liabilities	1,348	1,509
Total liabilities at fair value	1,348	1,509
Level I | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	709,592	574,337
Derivative assets	0	0
Mortgage servicing rights	0
Total assets at fair value	752,819	660,038
Derivative Liabilities	0	0
Total liabilities at fair value	0	0
Level II | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	5,864,589	5,500,192
Derivative assets	4,688	1,912
Mortgage servicing rights	0
Total assets at fair value	5,974,148	5,620,096
Derivative Liabilities	0	817
Total liabilities at fair value	0	817
Level III | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	12,174	9,696
Derivative assets	0	1
Mortgage servicing rights	1,561
Total assets at fair value	13,735	9,697
Derivative Liabilities	1,348	692
Total liabilities at fair value	1,348	692
Loaned securities | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	23,366	9,803
Loaned securities | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	12
Loaned securities | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	104,859	117,992
Loaned securities | Fair Value, Measurements, Recurring | Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	19,861	75,898
Loaned securities | Level I | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	23,366	9,803
Loaned securities | Level I | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	0
Loaned securities | Level I | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	0	0
Loaned securities | Level I | Fair Value, Measurements, Recurring | Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	19,861	75,898
Loaned securities | Level II | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	0	0
Loaned securities | Level II | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	12
Loaned securities | Level II | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	104,859	117,992
Loaned securities | Level II | Fair Value, Measurements, Recurring | Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	0	0
Loaned securities | Level III | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	0	0
Loaned securities | Level III | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	0
Loaned securities | Level III | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	0	0
Loaned securities | Level III | Fair Value, Measurements, Recurring | Equity securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Less: loaned securities	0	0
Fixed-maturities available for sale | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	5,176,521	5,188,228
Fixed-maturities available for sale | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	134,694	134,593
Fixed-maturities available for sale | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	152,959	142,785
Fixed-maturities available for sale | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	2,409,183	2,511,905
Fixed-maturities available for sale | Fair Value, Measurements, Recurring | RMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	1,060,805	1,014,071
Fixed-maturities available for sale | Fair Value, Measurements, Recurring | CMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	495,615	558,383
Fixed-maturities available for sale | Fair Value, Measurements, Recurring | CLO
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	515,339	487,849
Fixed-maturities available for sale | Fair Value, Measurements, Recurring | Other ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	360,171	284,559
Fixed-maturities available for sale | Fair Value, Measurements, Recurring | Foreign government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value		5,087
Fixed-maturities available for sale | Fair Value, Measurements, Recurring | Mortgage insurance-linked notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	47,755	48,996
Fixed-maturities available for sale | Level I | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	125,468	124,734
Fixed-maturities available for sale | Level I | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	125,468	124,734
Fixed-maturities available for sale | Level I | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level I | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level I | Fair Value, Measurements, Recurring | RMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level I | Fair Value, Measurements, Recurring | CMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level I | Fair Value, Measurements, Recurring | CLO
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level I | Fair Value, Measurements, Recurring | Other ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level I | Fair Value, Measurements, Recurring | Foreign government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value		0
Fixed-maturities available for sale | Level I | Fair Value, Measurements, Recurring | Mortgage insurance-linked notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level II | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	5,051,053	5,063,494
Fixed-maturities available for sale | Level II | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	9,226	9,859
Fixed-maturities available for sale | Level II | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	152,959	142,785
Fixed-maturities available for sale | Level II | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	2,409,183	2,511,905
Fixed-maturities available for sale | Level II | Fair Value, Measurements, Recurring | RMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	1,060,805	1,014,071
Fixed-maturities available for sale | Level II | Fair Value, Measurements, Recurring | CMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	495,615	558,383
Fixed-maturities available for sale | Level II | Fair Value, Measurements, Recurring | CLO
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	515,339	487,849
Fixed-maturities available for sale | Level II | Fair Value, Measurements, Recurring | Other ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	360,171	284,559
Fixed-maturities available for sale | Level II | Fair Value, Measurements, Recurring | Foreign government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value		5,087
Fixed-maturities available for sale | Level II | Fair Value, Measurements, Recurring | Mortgage insurance-linked notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	47,755	48,996
Fixed-maturities available for sale | Level III | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level III | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level III | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level III | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level III | Fair Value, Measurements, Recurring | RMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level III | Fair Value, Measurements, Recurring | CMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level III | Fair Value, Measurements, Recurring | CLO
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level III | Fair Value, Measurements, Recurring | Other ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Fixed-maturities available for sale | Level III | Fair Value, Measurements, Recurring | Foreign government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value		0
Fixed-maturities available for sale | Level III | Fair Value, Measurements, Recurring | Mortgage insurance-linked notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Trading securities | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	91,928	106,423
Trading securities | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	57,728	70,844
Trading securities | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	24,129	24,913
Trading securities | Fair Value, Measurements, Recurring | RMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	5,440	5,930
Trading securities | Fair Value, Measurements, Recurring | CMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	4,631	4,736
Trading securities | Level I | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Trading securities | Level I | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Trading securities | Level I | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Trading securities | Level I | Fair Value, Measurements, Recurring | RMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Trading securities | Level I | Fair Value, Measurements, Recurring | CMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Trading securities | Level II | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	91,928	106,423
Trading securities | Level II | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	57,728	70,844
Trading securities | Level II | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	24,129	24,913
Trading securities | Level II | Fair Value, Measurements, Recurring | RMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	5,440	5,930
Trading securities | Level II | Fair Value, Measurements, Recurring | CMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	4,631	4,736
Trading securities | Level III | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Trading securities | Level III | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Trading securities | Level III | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Trading securities | Level III | Fair Value, Measurements, Recurring | RMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Trading securities | Level III | Fair Value, Measurements, Recurring | CMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Equity securities | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	143,314	89,057
Equity securities | Level I | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	132,827	81,170
Equity securities | Level II | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	3,941	5,387
Equity securities | Level III | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	6,546	2,500
Mortgage loans held for sale | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	458,096	32,755
Mortgage loans held for sale | Level I | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Mortgage loans held for sale | Level II | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	458,096	32,755
Mortgage loans held for sale | Level III | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Other investments | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	5,628	7,196
Other investments | Level I | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Other investments | Level II | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Other investments | Level III | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	5,628	7,196
Short-term investments | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	710,868	660,566
Short-term investments | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	174,339
Short-term investments | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	3,599	2,700
Short-term investments | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	95,210	150,930
Short-term investments | Fair Value, Measurements, Recurring | CMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value		1,347
Short-term investments | Fair Value, Measurements, Recurring | Other ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	12,161	1,158
Short-term investments | Fair Value, Measurements, Recurring | Other investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	148,601	135,998
Short-term investments | Fair Value, Measurements, Recurring | Money market instruments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	276,958	368,433
Short-term investments | Level I | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	451,297	368,433
Short-term investments | Level I | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	174,339
Short-term investments | Level I | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Short-term investments | Level I | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Short-term investments | Level I | Fair Value, Measurements, Recurring | CMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value		0
Short-term investments | Level I | Fair Value, Measurements, Recurring | Other ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Short-term investments | Level I | Fair Value, Measurements, Recurring | Other investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Short-term investments | Level I | Fair Value, Measurements, Recurring | Money market instruments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	276,958	368,433
Short-term investments | Level II | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	259,571	292,133
Short-term investments | Level II | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0
Short-term investments | Level II | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	3,599	2,700
Short-term investments | Level II | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	95,210	150,930
Short-term investments | Level II | Fair Value, Measurements, Recurring | CMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value		1,347
Short-term investments | Level II | Fair Value, Measurements, Recurring | Other ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	12,161	1,158
Short-term investments | Level II | Fair Value, Measurements, Recurring | Other investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	148,601	135,998
Short-term investments | Level II | Fair Value, Measurements, Recurring | Money market instruments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Short-term investments | Level III | Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Short-term investments | Level III | Fair Value, Measurements, Recurring | U.S. government and agency securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0
Short-term investments | Level III | Fair Value, Measurements, Recurring | State and municipal obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Short-term investments | Level III | Fair Value, Measurements, Recurring | Corporate bonds and notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Short-term investments | Level III | Fair Value, Measurements, Recurring | CMBS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value		0
Short-term investments | Level III | Fair Value, Measurements, Recurring | Other ABS
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Short-term investments | Level III | Fair Value, Measurements, Recurring | Other investments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Short-term investments | Level III | Fair Value, Measurements, Recurring | Money market instruments
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments at fair value	0	0
Partnership investments | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other invested assets—at fair value	$ 2,000	$ 1,000