Fair Value of Financial Instruments - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) security	Dec. 31, 2019 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of investment portfolio fair value pricing services or index price	91.90%	94.10%
Net investment losses included in net income related to financial assets | $	$ 277	$ 1,067
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of hard-to-value fixed maturity securities | security	100
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of hard-to-value fixed maturity securities | security	150
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of invested assets in total investment portfolio Level 3 recurring	5.30%
Net investment gain (loss) | $	$ (11,500)	$ (12,600)