Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net income	$ 106,480	$ 84,941
Other comprehensive income (loss), before tax:
Change in net unrealized gain/loss on securities available for sale during the period	(178,904)	33,811
Change in net unrealized gain on securities transferred to held to maturity	(2,619)	(6,286)
Reclassification adjustment for net (gains) losses included in net income	19	0
Total securities available for sale and transferred securities, before tax amount	(181,504)	27,525
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)	1,250	1,357
Total defined-benefit post-retirement benefit plans	1,250	1,357
Other comprehensive income (loss), before tax	(180,254)	28,882
Deferred tax expense (benefit) related to other comprehensive income	(37,853)	10,109
Other comprehensive income (loss), net of tax	(142,401)	18,773
Comprehensive income (loss)	$ (35,921)	$ 103,714