Loans and Leases - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest receivable	$ 102,300,000		$ 102,300,000			$ 106,500,000
Jumbo residential mortgage loans	35,535,824,000		35,535,824,000			$ 34,497,464,000
Impairment charges	$ 0	$ 21,000	$ 224,000	$ 21,000
Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Jumbo residential mortgage loans					$ 423,000,000.0