Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Changes in accumulated other comprehensive income
Beginning balance	$ 384,754	$ 394,169
Other comprehensive income (loss)	5,474	(18,463)
Balance at end of period	404,649	380,400
Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income
Beginning balance	(36,515)	5,312
Other comprehensive income (loss) before reclassification	6,956	(23,368)
Federal income tax expense	(1,460)	4,907
Other comprehensive income (loss) before reclassification, net of tax	5,496	(18,461)
Amounts reclassified from AOCI	(28)	(2)
Federal income tax expense	6
Amounts reclassified from AOCI, net of tax	(22)	(2)
Other comprehensive income (loss)	5,474	(18,463)
Balance at end of period	$ (31,041)	$ (13,151)