Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net income	$ 177,653	$ 99,102
Other comprehensive income (loss), before tax:
Change in net unrealized gain/loss on securities available for sale during the period	260,269	(910,795)
Change in net unrealized gain on securities transferred to held to maturity	(160)	(209)
Reclassification adjustment for net (gains) losses included in net income	(21)	0
Total securities available for sale and transferred securities, before tax amount	260,088	(911,004)
Defined-benefit post-retirement benefit plans:
Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit)	870	741
Total defined-benefit post-retirement benefit plans	870	741
Other comprehensive income (loss), before tax	260,958	(910,263)
Deferred tax expense (benefit)	54,802	(191,155)
Other comprehensive income (loss), net of tax	206,156	(719,108)
Comprehensive income (loss)	$ 383,809	$ (620,006)