Retirement Plans (Components of Net Periodic Benefits Cost) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2,855	$ 2,620	$ 8,584	$ 8,996
Interest cost	3,756	3,552	10,881	9,982
Expected return on plan assets	(11,714)	(11,463)	(34,900)	(34,854)
Amortization of net (gain) or loss and prior service costs	450	717	2,380	4,471
Special termination benefits				16,052
Net periodic benefit cost	(4,653)	(4,574)	(13,055)	4,647
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	25	23	75	71
Interest cost	77	91	230	257
Amortization of net (gain) or loss and prior service costs	(139)	(192)	(417)	(501)
Special termination benefits				4,137
Net periodic benefit cost	$ (37)	$ (78)	$ (112)	$ 3,964