Fair Value - Rollforward of Level 3 assets and liabilities (Details) - Recurring - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021		Sep. 30, 2022	Sep. 30, 2021
Other liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		$ (16,205)	$ (466)		$ (16,960)	$ (461)
Total gains or (losses) (realized/unrealized) - included in earnings	[1]	(89)	0		(284)	0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income		965	0		1,915	0
Purchases, issuances, sales and settlements
Purchases		0	(17,345)		0	(17,345)
Issuances		0	0		0	0
Sales		0	0	[2]	0	0	[2]
Settlements		1,908	0		1,908	(5)
Transfers in and/or out of Level 3		0	0		0	0
Balance at end of period		(13,421)	(17,811)		(13,421)	(17,811)
Available for sale | Structured securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	[3]	2,867	3,424		3,347	3,426
Total gains or (losses) (realized/unrealized) - included in earnings	[1],[3]	(601)	10		(592)	(46)
Total gains or (losses) (realized/unrealized) - included in other comprehensive income	[3]	144	10		(1)	67
Purchases, issuances, sales and settlements
Purchases	[3]	0	0		0	0
Issuances	[3]	0	0		0	0
Sales	[3]	(2,051)	0	[2]	(2,051)	0	[2]
Settlements	[3]	(359)	0		(703)	(3)
Transfers in and/or out of Level 3	[3]	0	0		0	0
Balance at end of period	[3]	0	3,444		0	3,444
Available for sale | Corporate bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		3,570	13		13	13
Total gains or (losses) (realized/unrealized) - included in earnings	[1]	52	0		52	0
Total gains or (losses) (realized/unrealized) - included in other comprehensive income		(59)	0		(59)	0
Purchases, issuances, sales and settlements
Purchases		0	0		0	0
Issuances		0	0		0	0
Sales		(3,550)	0	[2]	(3,550)	0	[2]
Settlements		0	0		0	0
Transfers in and/or out of Level 3		0	0		3,557	0
Balance at end of period		13	13		13	13
Fair value option | Corporate bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		0	998		0	985
Total gains or (losses) (realized/unrealized) - included in earnings	[1]	0	0		0	13
Total gains or (losses) (realized/unrealized) - included in other comprehensive income		0	0		0	0
Purchases, issuances, sales and settlements
Purchases		0	0		0	0
Issuances		0	0		0	0
Sales		0	(998)	[2]	0	(998)	[2]
Settlements		0	0		0	0
Transfers in and/or out of Level 3		0	0		0	0
Balance at end of period		0	0		0	0
Fair value option | Other investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		33,331	73,900		27,981	67,103
Total gains or (losses) (realized/unrealized) - included in earnings	[1]	116	0		150	881
Total gains or (losses) (realized/unrealized) - included in other comprehensive income		0	0		0	0
Purchases, issuances, sales and settlements
Purchases		1,458	0		12,228	13,003
Issuances		0	0		0	0
Sales		(667)	(44,143)	[2]	(3,138)	(51,230)	[2]
Settlements		0	0		(2,983)	0
Transfers in and/or out of Level 3		0	0		0	0
Balance at end of period		34,238	29,757		34,238	29,757
Fair value option | Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		4,392	73,678		4,748	68,988
Total gains or (losses) (realized/unrealized) - included in earnings	[1]	200	38		(156)	4,728
Total gains or (losses) (realized/unrealized) - included in other comprehensive income		0	0		0	0
Purchases, issuances, sales and settlements
Purchases		0	0		0	0
Issuances		0	0		0	0
Sales		0	(69,181)	[2]	0	(69,181)	[2]
Settlements		0	0		0	0
Transfers in and/or out of Level 3		0	0		0	0
Balance at end of period		4,592	4,535		4,592	4,535
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period		2,906	49,136		2,918	42,015
Total gains or (losses) (realized/unrealized) - included in earnings	[1]	133	11		(103)	1,837
Total gains or (losses) (realized/unrealized) - included in other comprehensive income		0	0		0	0
Purchases, issuances, sales and settlements
Purchases		0	208		227	5,503
Issuances		0	0		0	0
Sales		0	(46,773)	[2]	(3)	(46,773)	[2]
Settlements		0	0		0	0
Transfers in and/or out of Level 3		0	0		0	0
Balance at end of period		$ 3,039	$ 2,582		$ 3,039	$ 2,582

[1] Gains or losses were included in net realized gains (losses).

[2] Sales for the 2021 periods primarily related to the Company’s deconsolidation of Somers..

[3] Includes asset backed securities, residential mortgage backed securities and commercial mortgage backed securities.