Loans and Leases - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Residual value of leased assets	$ 277,100	$ 277,100
Depreciation and amortization		308,638	$ 204,778	$ 191,824
Premises and equipment, net	533,138	533,138	427,534
Recorded investment in loans and leases sold, including accrued interest	199,786	199,786	90,664
Gains on sale of loans, net		26,308	33,695	45,318
Impairment charges on interest-only strips		62	$ 661	$ 1,600
Premises and equipment leased under finance leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Depreciation and amortization		76,400
Premises and equipment, net	289,700	$ 289,700
Automobile Loan | Consumer Loan Portfolio
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded investment in loans and leases sold, including accrued interest					$ 1,100,000
Gains on sale of loans, net	$ 27,500