Investments - Gross Unrealized Losses of Fixed Maturities and Equity Securities in Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2020 USD ($) security	Dec. 31, 2019 USD ($) security
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less	$ 562,450	$ 478,866
Fixed maturity securities, Fair Value, More than 12 Months	422,797	472,720
Fixed maturity securities, Fair Value, Total	985,247	951,586
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less	22,533	5,734
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months	5,849	7,880
Fixed maturity securities, Gross Unrealized Losses, Total	$ 28,382	$ 13,614
Number of positions with a gross unrealized loss, 12 Months or Less \| security	308	330
Number of position with a gross unrealized loss, more than 12 months \| security	123	137
Number of position with a gross unrealized loss, Total \| security	431	467
Fair value as a percentage of total fixed maturities and equity securities fair value, 12 Months or Less	8.90%	8.30%
Fair value as a percentage of total fixed maturities and equity securities fair value, more than 12 months	6.70%	8.20%
Fair value as a percentage of total fixed maturities and equity securities fair value, Total	15.60%	16.50%
Mortgage-backed securities
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less	$ 4,842	$ 72,422
Fixed maturity securities, Fair Value, More than 12 Months	2,644	2,620
Fixed maturity securities, Fair Value, Total	7,486	75,042
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less	75	1,282
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months	156	205
Fixed maturity securities, Gross Unrealized Losses, Total	231	1,487
Other
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less	95,919	38,341
Fixed maturity securities, Fair Value, More than 12 Months	0	1,527
Fixed maturity securities, Fair Value, Total	95,919	39,868
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less	1,033	619
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months	0	2
Fixed maturity securities, Gross Unrealized Losses, Total	1,033	621
Municipal bonds
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less	18,097	91,195
Fixed maturity securities, Fair Value, More than 12 Months	0	9,160
Fixed maturity securities, Fair Value, Total	18,097	100,355
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less	504	977
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months	0	603
Fixed maturity securities, Gross Unrealized Losses, Total	504	1,580
Foreign government bonds
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less	0	0
Fixed maturity securities, Fair Value, More than 12 Months	0	0
Fixed maturity securities, Fair Value, Total	0	0
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less	0	0
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months	0	0
Fixed maturity securities, Gross Unrealized Losses, Total	0	0
Corporate bonds
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less	126,619	58,198
Fixed maturity securities, Fair Value, More than 12 Months	10,879	16,622
Fixed maturity securities, Fair Value, Total	137,498	74,820
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less	3,768	886
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months	174	909
Fixed maturity securities, Gross Unrealized Losses, Total	3,942	1,795
Other asset-backed securities
Fixed maturity securities, Fair Value
Fixed maturity securities, Fair Value, 12 Months or Less	316,973	218,710
Fixed maturity securities, Fair Value, More than 12 Months	409,274	442,791
Fixed maturity securities, Fair Value, Total	726,247	661,501
Fixed maturity securities, Gross Unrealized Losses
Fixed maturity securities, Gross Unrealized Losses, 12 Months or Less	17,153	1,970
Fixed maturity securities, Gross Unrealized Losses, More than 12 Months	5,519	6,161
Fixed maturity securities, Gross Unrealized Losses, Total	$ 22,672	$ 8,131

Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract]

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Debt Securities, Available-for-sale, Unrealized Loss Position Abstract [Abstract]

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Fair value of positions with a gross unrealized loss as a percentage of total fixed maturities and equities fair value.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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