Pension Benefits, Other Postretirement Benefits and Employee Savings and Investment Plans (Summary of Changes in Fair Value of Guaranteed Deposit Account's Level 3 Assets) (Details) - Pension Benefits $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 35,296
Ending balance	33,462
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,347
Ending balance	1,290
Guaranteed deposit account
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,347
Ending balance	1,290
Guaranteed deposit account | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,347
Change in unrealized gain (loss)	(24)
Purchases, sales, issuances and settlements (net)	(33)
Ending balance	$ 1,290