Accumulated Other Comprehensive Loss - Changes, Net of Tax (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Net of tax
Balance	$ 2,656,912	$ 2,744,104
Other comprehensive loss	(395,809)	(75,039)
Balance	2,285,149	2,683,630
Accumulated Other Comprehensive Income (Loss)
Net of tax
Balance	(121,693)	31,604
Other comprehensive loss	(395,809)	(75,039)
Balance	(517,502)	(43,435)
Pensions and Other Benefits
Net of tax
Balance	(24,390)	(31,737)
Balance	(24,390)	(31,737)
Investment Securities.
Net of tax
Balance	(97,303)	63,341
Other comprehensive loss	(394,551)	(75,039)
Balance	(491,854)	$ (11,698)
Cash Flow Derivative Hedges
Net of tax
Other comprehensive loss	(1,258)
Balance	$ (1,258)