Investments - Summarized Fair Value and Gross Unrealized Losses on Securities Available for Sale (Details) $ in Thousands	Dec. 31, 2019 USD ($) security	Dec. 31, 2018 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	68	331
Less than 12 months, Fair value	$ 79,297	$ 279,093
Less than 12 months, Unrealized losses	$ (468)	$ (4,063)
12 months or longer, Number of issues \| security	42	281
12 months or longer, Fair value	$ 65,802	$ 337,226
12 months or longer, Unrealized losses	$ (557)	$ (8,548)
U.S. government obligations and agencies [Member] \| Fixed Maturities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	2	0
Less than 12 months, Fair value	$ 3,836	$ 0
Less than 12 months, Unrealized losses	$ (108)	$ 0
12 months or longer, Number of issues \| security	4	13
12 months or longer, Fair value	$ 23,186	$ 56,531
12 months or longer, Unrealized losses	$ (80)	$ (1,039)
Corporate bonds [Member] \| Fixed Maturities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	18	228
Less than 12 months, Fair value	$ 16,808	$ 210,152
Less than 12 months, Unrealized losses	$ (107)	$ (3,318)
12 months or longer, Number of issues \| security	7	160
12 months or longer, Fair value	$ 5,866	$ 131,225
12 months or longer, Unrealized losses	$ (34)	$ (3,418)
Mortgage-backed and asset-backed securities [Member] \| Fixed Maturities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	42	36
Less than 12 months, Fair value	$ 58,023	$ 57,487
Less than 12 months, Unrealized losses	$ (245)	$ (196)
12 months or longer, Number of issues \| security	26	103
12 months or longer, Fair value	$ 34,985	$ 148,436
12 months or longer, Unrealized losses	$ (361)	$ (3,959)
Municipal bonds [Member] \| Fixed Maturities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	0	6
Less than 12 months, Fair value	$ 0	$ 3,362
Less than 12 months, Unrealized losses	$ 0	$ (43)
12 months or longer, Number of issues \| security	1	0
12 months or longer, Fair value	$ 276	$ 0
12 months or longer, Unrealized losses	$ (4)	$ 0
Redeemable preferred stock [Member] \| Fixed Maturities [Member]
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	6	61
Less than 12 months, Fair value	$ 630	$ 8,092
Less than 12 months, Unrealized losses	$ (8)	$ (506)
12 months or longer, Number of issues \| security	4	5
12 months or longer, Fair value	$ 1,489	$ 1,034
12 months or longer, Unrealized losses	$ (78)	$ (132)

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of accumulated unrealized loss on 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 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without an allowance for credit loss. Includes beneficial interest in securitized financial asset.

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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 less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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