Employee Benefit Plans - Net Pension Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Components of net pension cost
Service cost - benefits earned during the year	$ 218	$ 338	$ 473	$ 745
Interest costs on projected benefit obligations	349	291	714	587
Expected return on plan assets	(544)	(583)	(1,089)	(1,141)
Expected administrative expenses	29	29	57	59
Amortization of unrecognized net loss	(178)	0	(320)	0
Net periodic pension cost	$ (126)	$ 75	$ (165)	$ 250