Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Net income	$ 162,118	$ 119,114	$ 339,771	$ 218,216
Other comprehensive income (loss), before tax:
Change in net unrealized gain/loss on securities available for sale during the period	(206,863)	(636,523)	53,406	(1,547,318)
Change in net unrealized gain on securities transferred to held to maturity	(162)	(189)	(322)	(398)
Reclassification adjustment for net (gains) losses included in net income	(33)	0	(54)	0
Total securities available for sale and transferred securities, before tax amount	(207,058)	(636,712)	53,030	(1,547,716)
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	1,740	1,482
Total defined-benefit post-retirement benefit plans	870	741	1,740	1,482
Other comprehensive income (loss), before tax	(206,188)	(635,971)	54,770	(1,546,234)
Deferred tax expense (benefit)	(43,299)	(133,555)	11,503	(324,710)
Other comprehensive income (loss), net of tax	(162,889)	(502,416)	43,267	(1,221,524)
Comprehensive income (loss)	$ (771)	$ (383,302)	$ 383,038	$ (1,003,308)