Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Valuation Allowance [Line Items]
Tax Credit Carryforward, Valuation Allowance	$ 0
Deferred Tax Assets, Operating Loss Carryforwards	48,300,000
Deferred tax assets, state net operating loss carryforward		$ 24,600,000
Increase in tax expense attributable to revaluation of deferred tax assets		(15,736,000)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	429,000	564,000	$ 450,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance of unrecognized tax benefits	28,255,000	29,004,000	28,879,000
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions	(683,000)	(1,054,000)	(44,000)
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	6,554,000	1,433,000	169,000
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	(1,900,000)	(1,128,000)	0
Ending balance of unrecognized tax benefits	32,226,000	28,255,000	29,004,000
Current tax expense
Federal	68,984,000	95,151,000	87,992,000
State	11,095,000	21,523,000	6,116,000
Total current tax expense	80,079,000	116,674,000	94,108,000
Deferred Income Tax Expense (Benefit)
Federal	50,522,000	(10,944,000)	115,392,000
State	4,076,000	(2,433,000)	10,446,000
Total deferred tax expense	54,598,000	(13,377,000)	125,838,000
Total income tax expense	$ 134,677,000	$ 103,297,000	219,946,000
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Federal statutory rate	21.00%	35.00%
Income taxes at federal statutory rates	$ 124,330,000	$ 105,758,000	190,294,000
Nontaxable income on loans, leases and investments, net of nondeductible expenses	(1,639,000)	(1,796,000)	(2,525,000)
Excess tax benefits of compensation	1,070,000	371,000	0
State and local income taxes, including any change in valuation allowance, net of federal income tax benefit	11,985,000	15,081,000	10,765,000
Effect of federal rate change	0		25,762,000
Tax credits net of amortization	(4,474,000)	(2,891,000)	(4,840,000)
Other, net	3,405,000	2,510,000	490,000
Total income tax expense	134,677,000	103,297,000	$ 219,946,000
Deferred Tax Assets, Net [Abstract]
Allowance for loan and lease losses	53,073,000	53,391,000
Operating lease liabilities	17,752,000
Executive separation from service agreements	12,334,000	7,927,000
Federal net operating loss carryforward	11,085,000	6,862,000
Net unrealized loss included in comprehensive income	0	32,663,000
Employee compensation	13,313,000	11,145,000
Deferred Tax Assets, FDIC-Assisted Transaction Timing Differences	8,678,000	7,622,000
Deferred Tax Assets, Other reserves	5,001,000	5,574,000
Other	10,698,000	9,555,000
Deferred tax asset	131,934,000	134,739,000
Deferred Tax Liabilities, accelerated depreciation	51,249,000	4,987,000
Lease financing activities	8,101,000	12,674,000
Operating lease assets	17,837,000
Net unrealized gain on securities included in accumulated other comprehensive loss	1,821,000	0
Net deferred loan fees and costs	11,781,000	10,651,000
Intangible assets	9,148,000	11,713,000
Deferred Tax Liability, Security, loan and debt valuations	5,767,000	4,557,000
Pension liability	5,079,000	6,287,000
Other	15,993,000	1,722,000
Deferred tax liability	126,776,000	52,591,000
Net deferred tax assets	$ 5,158,000	$ 82,148,000