Postretirement Benefits - Activity for the SERP (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Retirement Benefits [Abstract]
Premiums paid for insurance coverage	$ 443	$ 443
Total investments:
Company owned life insurance	54,788		$ 54,681
Exchange traded funds	74,632		71,258
Total investments of SERP	$ 129,420		$ 125,939