Allowance for Loan and Lease Losses and Credit Quality Information - Interest Income for Loans and Leases in Non-accrual Status (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Contractual interest due on non-accrual loans and leases	$ 10,921	$ 15,009	$ 20,604
Interest income recognized on non-accrual loans and leases	1,351	2,982	4,152
Unrecognized interest income	$ 9,570	$ 12,027	$ 16,452

Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18794-111554

Name:	us-gaap_LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration