CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 102,374	$ 81,891	$ 285,243	$ 271,689
Unrealized gains and losses on available for sale securities
Net (losses) gains arising during the period	(1,262)	8,135	27,819	42,890
Less reclassification adjustment for net losses included in net income	36	72	94	90
Total	(1,226)	8,207	27,913	42,980
Unrealized gains and losses on derivatives (cash flow hedges)
Net gains (losses) on derivatives arising during the period	83	76	(2,254)	(989)
Less reclassification adjustment for net losses included in net income	1,127	324	1,257	806
Total	1,210	400	(997)	(183)
Defined benefit pension plan
Amortization of actuarial net loss	171	56	515	166
Total other comprehensive income	155	8,663	27,431	42,963
Total comprehensive income	$ 102,529	$ 90,554	$ 312,674	$ 314,652