Reserves for Losses and Loss Adjustment Expenses (Incurred and Paid Claims Development - Runoff) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) claim	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable net prior year development	$ 112,300	$ 6,000
Incurred claims and claim adjustment expenses related to current year	117,644	151,603
Total incurred	323,499	275,244
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Total paid	292,089	279,046
Liabilities for unpaid claims and claim adjustment expenses, net of reinsurance	460,176	428,766	$ 432,568
Runoff Segment [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total incurred	1,849,682
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Total paid	1,497,543
All outstanding liabilities before 2012, net of reinsurance	5,240
Liabilities for unpaid claims and claim adjustment expenses, net of reinsurance	357,379
Runoff Segment [Member] | Loss Adjustment Expenses Recognized In 2013 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable net prior year development		153,479	153,426	$ 150,927	$ 145,545	$ 144,604	$ 142,174	$ 133,845	$ 131,174	$ 133,308
Incurred claims and claim adjustment expenses related to current year	155,365
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 337
Cumulative number of reported claims | claim	10,457
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 153,384	152,471	151,959	149,477	143,294	133,999	123,429	98,497	72,326	$ 36,791
Runoff Segment [Member] | Loss Adjustment Expenses Recognized In 2014 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable net prior year development		167,224	167,409	163,523	160,720	153,753	143,821	137,889	145,566
Incurred claims and claim adjustment expenses related to current year	169,142
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 45
Cumulative number of reported claims | claim	11,108
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 167,691	167,298	166,772	165,114	154,686	131,463	103,962	76,202	$ 42,031
Runoff Segment [Member] | Loss Adjustment Expenses Recognized in 2015 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable net prior year development		188,674	187,498	181,088	173,980	164,093	145,913	151,185
Incurred claims and claim adjustment expenses related to current year	191,804
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 1,359
Cumulative number of reported claims | claim	11,752
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 182,952	180,441	175,438	171,226	161,942	124,963	74,733	$ 40,656
Runoff Segment [Member] | Loss Adjustment Expenses Recognized in 2016 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable net prior year development		185,696	186,805	184,115	166,798	161,614	154,909
Incurred claims and claim adjustment expenses related to current year	186,239
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 20
Cumulative number of reported claims | claim	12,066
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 181,150	180,605	179,266	167,310	138,231	86,836	$ 42,653
Runoff Segment [Member] | Loss Adjustment Expenses Recognized in 2017 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable net prior year development		228,885	199,567	178,850	159,000	179,495
Incurred claims and claim adjustment expenses related to current year	245,127
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 1,031
Cumulative number of reported claims | claim	12,091
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 203,169	201,100	188,053	160,742	111,296	$ 45,288
Runoff Segment [Member] | Loss Adjustment Expenses Recognized In 2018 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable net prior year development		212,651	157,776	163,446	170,636
Incurred claims and claim adjustment expenses related to current year	232,979
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 1,209
Cumulative number of reported claims | claim	11,593
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 214,460	189,161	174,348	132,424	$ 95,327
Runoff Segment [Member] | Loss Adjustment Expenses Recognized In 2019 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable net prior year development		189,509	178,072	176,760
Incurred claims and claim adjustment expenses related to current year	226,125
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 12,028
Cumulative number of reported claims | claim	12,204
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 188,010	140,058	115,879	$ 75,698
Runoff Segment [Member] | Loss Adjustment Expenses Recognized In 2020 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable net prior year development		199,806	207,793
Incurred claims and claim adjustment expenses related to current year	226,275
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 27,008
Cumulative number of reported claims | claim	16,186
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 144,064	91,963	$ 39,844
Runoff Segment [Member] | Loss Adjustment Expenses Recognized In 2021 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable net prior year development		130,322
Incurred claims and claim adjustment expenses related to current year	132,133
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 28,476
Cumulative number of reported claims | claim	13,686
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 52,082	$ 22,729
Runoff Segment [Member] | Loss Adjustment Expenses Recognized In 2022 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to current year	84,493
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 57,852
Cumulative number of reported claims | claim	4,728
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to current year	$ 10,582