Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 52,686	$ 67,207	$ 92,869	$ 130,849
Change in net unrealized gain on available-for-sale ("AFS") securities, net of tax	27,834	17,994	45,420	34,783
Change in net unrealized loss on cash flow hedge, net of tax	(1,272)	0	(1,272)	0
Change in pension plan assets, net of tax	1,113	909	2,225	1,819
Comprehensive income, net of tax	$ 80,361	$ 86,110	$ 139,242	$ 167,451