Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net income	$ 80,219	$ 75,850	$ 220,542	$ 221,090
Other comprehensive income (loss), before tax:
Change in net unrealized gain/loss on securities available for sale during the period	(95,641)	86,445	191,865	7,704
Change in net unrealized gain on securities transferred to held to maturity	(7,278)	(8,831)	(24,629)	(24,925)
Reclassification adjustment for net (gains) losses included in net income	37	52	(14,866)	(176)
Total securities available for sale and transferred securities, before tax amount	(102,882)	77,666	152,370	(17,397)
Defined-benefit post-retirement benefit plans:
Change in the net actuarial gain/loss	1,585	1,748	4,691	5,246
Remeasurement of projected benefit obligation related to SERP	0	0	(862)	0
Reclassification adjustment for SERP settlement costs included in net income	0	0	187	0
Total defined-benefit post-retirement benefit plans	1,585	1,748	4,016	5,246
Other comprehensive income (loss), before tax	(101,297)	79,414	156,386	(12,151)
Deferred tax expense (benefit) related to other comprehensive income	(35,453)	27,795	54,736	(4,253)
Other comprehensive income (loss), net of tax	(65,844)	51,619	101,650	(7,898)
Comprehensive income (loss)	$ 14,375	$ 127,469	$ 322,192	$ 213,192