Pension and Other Post-Retirement Benefits (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pension benefits
Components of net periodic benefit cost
Service cost	$ 1,425	$ 1,560	$ 2,850	$ 3,120
Interest cost	2,205	2,245	4,410	4,490
Expected return on plan assets	(3,776)	(3,479)	(7,552)	(6,958)
Amortization of prior service cost	(563)	(564)	(1,126)	(1,128)
Amortization of the net loss	18	20	36	40
Net periodic cost	(691)	(218)	(1,382)	(436)
Other post-retirement benefits
Components of net periodic benefit cost
Service cost	0	0	0	0
Interest cost	15	7	30	14
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	0	0	0	0
Amortization of the net loss	10	10	20	20
Net periodic cost	$ 25	$ 17	$ 50	$ 34