Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 92,152	$ 103,784	$ 293,886	$ 196,653
Change in net unrealized (loss) gain on available-for-sale ("AFS") securities, net of tax	(13,777)	8,180	(36,305)	53,600
Change in net unrealized gain (loss) on cash flow hedge, net of tax	1,377	678	10,320	(594)
Change in pension plan assets, net of tax	638	988	2,376	3,213
Comprehensive income, net of tax	$ 80,390	$ 113,630	$ 270,277	$ 252,872