CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - 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	$ 122,580	$ 102,374	$ 358,802	$ 285,243
Unrealized gains and losses on available for sale securities
Net (losses) gains arising during the period	(3,953)	(1,262)	(15,860)	27,819
Less reclassification adjustment for net (gains) losses included in net income	(613)	36	(493)	94
Total	(4,566)	(1,226)	(16,353)	27,913
Unrealized gains and losses on derivatives (cash flow hedges)
Net (losses) gains on derivatives arising during the period	(96)	83	(69)	(2,254)
Less reclassification adjustment for net losses included in net income	743	1,127	1,928	1,257
Total	647	1,210	1,859	(997)
Defined benefit pension plan
Amortization of actuarial net loss	279	171	837	515
Total other comprehensive (loss) income	(3,640)	155	(13,657)	27,431
Total comprehensive income	$ 118,940	$ 102,529	$ 345,145	$ 312,674