Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other comprehensive (loss) income, net of tax:
Net income	$ 220,621	$ 382,723	$ 360,418
Investment securities available-for-sale	50,173	88,625	(43,427)
Derivative instruments	29,102	129	5,703
Total defined benefit pension and postretirement benefit plans	(947)	5,826	(1,397)
Other comprehensive (loss) income, net of tax	78,328	94,580	(39,121)
Comprehensive income	$ 298,949	$ 477,303	$ 321,297