Income Taxes - Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Allowance for loan and lease losses	$ 33,546	$ 41,339
Stock compensation and deferred compensation plans	32,686	21,150
Net operating losses and other carryforwards	20,591	16,452
Debt securities available for sale	9,235	5,345
Accrued expense	2,524	2,507
Other	1,900	3,603
Deferred tax assets	100,482	90,396
Valuation allowance	(14,291)	(14,267)
Total deferred tax assets, net of valuation allowance	86,191	76,129
Deferred tax liabilities
Lease financing	297,603	246,221
Premises and equipment	40,130	30,109
Loan fees and discounts	17,465	12,489
Prepaid expenses	7,921	8,047
Goodwill and other intangibles	2,290	2,475
Other	7,319	4,715
Total deferred tax liabilities	372,728	304,056
Net deferred tax liabilities	286,537	$ 227,927
Charitable contribution carryforwards	200
State
Deferred tax assets:
Net operating losses and other carryforwards	3,300
Federal
Deferred tax assets:
Net operating losses and other carryforwards	$ 2,800