Accumulated Other Comprehensive Income (Reclassification out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Loan interest income	$ 162,492	$ 132,540	$ 456,143	$ 381,996
Income before income taxes	82,423	66,491	230,528	200,468
Income tax provision	(17,481)	(13,474)	(49,256)	(40,559)
Net Income	64,942	53,017	181,272	159,909
Compensation and employee benefits	60,744	54,679	181,209	159,865
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains and Losses on Available-for-Sale Debt Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Debt Securities, Available-for-sale, Realized Gain	0	0	0	314
Income before income taxes	2,718	606	6,830	1,370
Income tax provision	(632)	(141)	(1,588)	(319)
Net Income	2,086	465	5,242	1,051
Reclassification out of Accumulated Other Comprehensive Income [Member] | Amortization of unrealized gains and losses related to available for sale securities transfer
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Loan interest income	2,718	606	6,830	1,056
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains and Losses on Pension Plan Liability [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	(130)	(149)	(392)	(448)
Income tax provision	30	35	91	104
Net Income	(100)	(114)	(301)	(344)
Compensation and employee benefits	(130)	(149)	(392)	(448)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized gains and losses from hedging instruments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	2,631	2,631	7,809	7,809
Income tax provision	(612)	(612)	(1,816)	(1,815)
Net Income	2,019	2,019	5,993	5,994
Loans	$ 2,631	$ 2,631	$ 7,809	$ 7,809