Accumulated Other Comprehensive Income (Details) - Accumulated Other Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Changes in accumulated other comprehensive income
Beginning balance	$ 4,686	$ (563)
Other comprehensive income (loss) before reclassification	(7,368)	2,632
Federal income tax (expense) benefit	1,547	(459)
Other comprehensive income (loss) before reclassification, net of tax	(5,821)	2,173
Amounts reclassified from AOCI	(15)	18
Federal income tax expense	3	(4)
Amounts reclassified from AOCI, net of tax	(12)	14
Other comprehensive income (loss)	(5,833)	2,187
Ending balance	$ (1,147)	$ 1,624