Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net income	$ 116,496	$ 106,480
Other comprehensive income (loss), before tax:
Change in net unrealized gain/loss on securities available for sale during the period	198,146	(178,904)
Change in net unrealized gain on securities transferred to held to maturity	(344)	(2,619)
Reclassification adjustment for net (gains) losses included in net income	0	19
Total securities available for sale and transferred securities, before tax amount	197,802	(181,504)
Defined-benefit post-retirement benefit plans:
Change in the net actuarial gain/loss	0	0
Reclassification adjustment for net amortization of actuarial gain/loss included in net income as a component of net periodic cost (benefit)	1,406	1,250
Total defined-benefit post-retirement benefit plans	1,406	1,250
Other comprehensive income (loss), before tax	199,208	(180,254)
Deferred tax expense (benefit) related to other comprehensive income	41,834	(37,853)
Other comprehensive income (loss), net of tax	157,374	(142,401)
Comprehensive income (loss)	$ 273,870	$ (35,921)