Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	$ 98,082,000	$ 77,422,000	$ 73,921,000
Current State and Local Tax Expense (Benefit)	19,270,000	4,538,000	4,822,000
Total current tax expense (benefit)	117,352,000	81,960,000	78,743,000
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	(45,450,000)	12,446,000	10,162,000
State	(12,865,000)	2,250,000	1,603,000
Deferred tax (expense) benefit	(58,315,000)	14,696,000	11,765,000
Income tax expense (benefit)	59,037,000	96,656,000	90,508,000
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax expense (benefit) at statutory rate	77,985,000	104,483,000	94,489,000
State excise tax expense, net of federal tax effect	5,059,000	5,363,000	5,076,000
Tax-exempt securities	(13,706,000)	(11,078,000)	(7,222,000)
Federal tax credits	(3,717,000)	(1,704,000)	(845,000)
Bank owned life insurance	(4,759,000)	(3,646,000)	(2,764,000)
Insurance premiums	(272,000)	(238,000)	(112,000)
Excess tax benefits associated with equity compensation	(417,000)	(1,011,000)	(2,966,000)
Other items	$ (1,136,000)	4,487,000	4,852,000
Federal income tax statutory rate	21.00%
Deferred Tax Assets, Net [Abstract]
Loan loss allowance	$ 72,316,000	23,051,000
Loans	14,694,000	20,808,000
Insurance	690,000	673,000
Accrued liability for supplemental retirement agreements	7,457,000	7,308,000
Restricted stock and stock options	9,181,000	10,515,000
Cash flow hedge	0	1,373,000
Equity Method Investments	171,000	425,000
Leases	23,894,000	22,782,000
Other real estate owned	2,287,000	691,000
Net federal operating loss carryforward and credits	1,796,000	5,954,000
Annual Incentive Compensation	8,712,000	12,626,000
Deferred Tax Assets Investment in Noncontrolled Affiliates	25,225,000	0
Allowance for off balance sheet credit exposures	6,069,000	618,000
Other deferred tax assets	2,559,000	2,501,000
Total deferred tax assets	175,051,000	109,325,000
Deferred Tax Liabilities, Net [Abstract]
Depreciation and amortization	14,418,000	12,455,000
Core deposit and other intangible assets	11,077,000	13,253,000
Securities	34,373,000	8,287,000
REIT dividends	1,366,000	1,650,000
FHLB related liabilities	1,798,000	925,000
Right-of-use assets and other leasing transactions	22,232,000	21,169,000
Subordinated debt	1,920,000	2,050,000
Partnership interests	0	3,534,000
Deferred Tax Liabilities, Derivatives	19,627,000	0
Other deferred tax liabilities	1,630,000	1,875,000
Total deferred tax liabilities	108,441,000	65,198,000
Net deferred tax assets	66,610,000	44,127,000
Unrecognized Tax Benefits	9,658,000	6,910,000	5,083,000	$ 2,838,000
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	2,748,000	1,827,000	2,245,000
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	0	0	0
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	0	0	0
Unrecognized Tax Benefits, Increase Resulting from Settlements with Taxing Authorities	0	0	$ 0
Tax Credit Carryforward, Amount	8,400,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 571,000	$ 0