Loans, Allowance for Loan Losses and Allowance for Unfunded Credit Commitments - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Receivables [Abstract]
Deferred loan fee income	$ 173,000	$ 148,000
Loans modified in TDRs	83,695	$ 147,793
Unfunded commitments available for funding	$ 2,700

Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Name:	us-gaap_LoansAndLeasesReceivableDeferredIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant