Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement Of Income And Comprehensive Income [Abstract]
Net Income	$ 54,834	$ 59,949
Other Comprehensive Income (Loss), Net of Tax:
Net Unrealized Losses on Investment Securities	(180,124)	(50,050)
Defined Benefit Plans	353	441
Total Other Comprehensive Loss	(179,771)	(49,609)
Comprehensive Income (Loss)	$ (124,937)	$ 10,340