Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net income	$ 116,015	$ 54,753
Other comprehensive income (loss), before tax:
Change in net unrealized gain/loss on securities available for sale during the period	(159,779)	230,118
Change in net unrealized gain on securities transferred to held to maturity	(259)	(377)
Reclassification adjustment for net (gains) losses included in net income	0	(108,989)
Total securities available for sale and transferred securities, before tax amount	(160,038)	120,752
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)	1,529	1,330
Total defined-benefit post-retirement benefit plans	1,529	1,330
Other comprehensive income (loss), before tax	(158,509)	122,082
Deferred tax expense (benefit)	(33,287)	25,637
Other comprehensive income (loss), net of tax	(125,222)	96,445
Comprehensive income (loss)	$ (9,207)	$ 151,198