Fair Value of Financial Instruments - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net investment losses included in net income related to financial assets	$ 32,000	$ 0	$ 8,000	$ 0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net investment losses included in net income related to financial assets			$ 0	0
Percentage of invested assets in total investment portfolio Level 3 recurring	6.30%		6.30%
Net realized investment losses	$ 6,000,000.0	$ 400,000	$ 900,000	$ 4,700,000