Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 0	$ 0
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	77,422,000	73,921,000	$ 63,496,000
Current State and Local Tax Expense (Benefit)	4,538,000	4,822,000	860,000
Total current tax expense (benefit)	81,960,000	78,743,000	64,356,000
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	12,446,000	10,162,000	26,339,000
State	2,250,000	1,603,000	1,826,000
Total deferred tax expense (benefit)	14,696,000	11,765,000	59,651,000
Income tax expense (benefit)	$ 96,656,000	$ 90,508,000	$ 124,007,000
Federal income tax statutory rate	21.00%	35.00%	35.00%
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax expense (benefit) at statutory rate	$ 104,483,000	$ 94,489,000	$ 104,295,000
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount	5,363,000	5,076,000	1,746,000
Tax-exempt securities	11,078,000	7,222,000	5,666,000
Federal tax credits	(1,704,000)	(845,000)	(434,000)
Bank owned life insurance	(3,646,000)	(2,764,000)	(2,778,000)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Life Insurance, Amount	(238,000)	(112,000)	(283,000)
Revaluation of deferred taxes	0	0	(31,486,000)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Amount	(1,011,000)	(2,966,000)	(5,366,000)
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount	4,487,000	4,852,000	1,007,000
Income tax expense (benefit)	96,656,000	90,508,000	124,007,000
Deferred Tax Assets, Net [Abstract]
Loan loss allowance	23,051,000	20,449,000
Loans	20,808,000	29,453,000
Insurance	673,000	1,955,000
Accrued liability for supplemental retirement agreements	7,308,000	6,231,000
Restricted stock and stock options	10,515,000	9,026,000
Securities	0	15,974,000
Cash flow hedge	1,373,000	459,000
Equity Method Investments	425,000	602,000
Leases	22,782,000	2,099,000
Other real estate owned	691,000	1,158,000
Net federal operating loss carryforward and credits	5,954,000	13,754,000
Annual Incentive Compensation	12,626,000	9,996,000
Other deferred tax assets	1,810,000	3,343,000
Total deferred tax assets	108,016,000	114,499,000
Deferred Tax Liabilities, Net [Abstract]
Depreciation and amortization	12,455,000	11,769,000
Core deposit and other intangible assets	13,253,000	11,475,000
Securities	6,978,000	0
REIT dividends	1,650,000	1,589,000
FHLB related liabilities	925,000	925,000
Right-of-use assets and other leasing transactions	21,169,000	639,000
Subordinated debt	2,050,000	1,134,000
Partnership interests	3,534,000	459,000
Other deferred tax liabilities	1,875,000	1,758,000
Total deferred tax liabilities	63,889,000	29,748,000
Net deferred tax assets	44,127,000	84,751,000
Unrecognized tax benefits, beginning of period	5,083,000	2,838,000	1,274,000
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	1,827,000	2,245,000	1,564,000
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
Unrecognized tax benefits, end of period	$ 6,910,000	$ 5,083,000	$ 2,838,000