Disclosures About Fair Value of Financial Instruments - Reconciliation of all Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Level 3) (Details) - Level 3 - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3)
Beginning balance January 1,	$ 559	$ 0
Total net realized investment gains/ (losses) and net change in unrealized appreciation/ (depreciation):
Included in net income	0	0
Included in other comprehensive income	0	0
Purchases	0	0
Sales	52	0
Transfers from Level 3	0	0
Transfers into Level 3	0	0
Ending balance March 31,	$ 507	$ 0