Reserves for Losses and Loss Adjustment Expenses (Incurred and Paid Claims Development - Programs) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) claim	Dec. 31, 2020 USD ($)	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 ($)	Dec. 31, 2012 USD ($)
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable (favorable) net prior year development	$ 6,040	$ 58,288
Incurred claims and claim adjustment expenses related to current year	269,204	326,919
Total incurred	275,244	406,907
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	177,571	185,407
Paid claims and allocated claim adjustment expenses related to current year	101,475	113,312
Total paid	279,046	320,419
Liabilities for unpaid claims and claim adjustment expenses, net of reinsurance	428,766	432,568	$ 346,080
Loss Adjustment Expenses Recognized In 2012 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years										$ 1,181
Specialty Programs Business Unit [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total incurred	37,861
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Total paid	30,453
Liabilities for unpaid claims and claim adjustment expenses, net of reinsurance	7,408
Specialty Programs Business Unit [Member] | Loss Adjustment Expenses Recognized In 2012 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable (favorable) net prior year development		2,045	2,045	$ 2,045	$ 2,045	$ 2,045	$ 3,885	$ 2,045	$ 2,045	3,001
Incurred claims and claim adjustment expenses related to current year	$ 2,045
Cumulative number of reported claims | claim	3
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 2,045	2,045	2,045	2,045	2,045	2,045	2,045	2,045	2,045	$ 2,045
Specialty Programs Business Unit [Member] | Loss Adjustment Expenses Recognized In 2013 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable (favorable) net prior year development		2,302	2,302	2,302	2,302	2,076	1,561	2,543	1,595
Incurred claims and claim adjustment expenses related to current year	$ 2,302
Cumulative number of reported claims | claim	2
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 2,302	2,302	2,302	2,302	2,302	2,076	1,561	1,561	$ 1,489
Specialty Programs Business Unit [Member] | Loss Adjustment Expenses Recognized In 2014 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable (favorable) net prior year development		1,575	1,575	1,575	1,575	2,039	666	1,623
Incurred claims and claim adjustment expenses related to current year	$ 1,575
Cumulative number of reported claims | claim	5
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 1,575	1,575	1,575	1,575	1,575	1,575	1,502	$ 758
Specialty Programs Business Unit [Member] | Loss Adjustment Expenses Recognized in 2015 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable (favorable) net prior year development		752	752	752	752	1,629	1,683
Incurred claims and claim adjustment expenses related to current year	$ 752
Cumulative number of reported claims | claim	2
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 752	752	752	752	752	1,629	$ 1,515
Specialty Programs Business Unit [Member] | Loss Adjustment Expenses Recognized in 2016 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable (favorable) net prior year development		1,178	1,178	1,178	1,200	478
Incurred claims and claim adjustment expenses related to current year	$ 1,178
Cumulative number of reported claims | claim	1
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 1,178	1,178	1,178	1,178	1,139	$ 1,139
Specialty Programs Business Unit [Member] | Loss Adjustment Expenses Recognized in 2017 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable (favorable) net prior year development		1,982	1,801	1,775	955
Incurred claims and claim adjustment expenses related to current year	1,982
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 7
Cumulative number of reported claims | claim	66
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 1,967	1,967	1,551	1,556	$ 36
Specialty Programs Business Unit [Member] | Loss Adjustment Expenses Recognized In 2018 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable (favorable) net prior year development		4,222	4,368	3,598
Incurred claims and claim adjustment expenses related to current year	4,222
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 42
Cumulative number of reported claims | claim	795
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 4,030	3,778	1,290	$ 911
Specialty Programs Business Unit [Member] | Loss Adjustment Expenses Recognized In 2019 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable (favorable) net prior year development		9,150	5,407
Incurred claims and claim adjustment expenses related to current year	9,078
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 673
Cumulative number of reported claims | claim	1,060
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 8,174	7,794	$ 4,501
Specialty Programs Business Unit [Member] | Loss Adjustment Expenses Recognized In 2020 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Total unfavorable (favorable) net prior year development		6,737
Incurred claims and claim adjustment expenses related to current year	7,107
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 848
Cumulative number of reported claims | claim	880
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to prior years	$ 5,563	$ 2,908
Specialty Programs Business Unit [Member] | Loss Adjustment Expenses Recognized In 2021 [Member]
Liability For Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Incurred claims and claim adjustment expenses related to current year	7,620
Total of incurred-but-not-reported liabilities plus expected development on reported claims	$ 3,322
Cumulative number of reported claims | claim	593
Liability For Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Paid claims and allocated claim adjustment expenses related to current year	$ 2,867