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Loans - Narrative, PCI Loans (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable held-for-sale, amount	$ 0	$ 0
Loans and Leases Receivable, Net of Deferred Income	$ 3,255,860,000	$ 3,245,170,000
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of PCI loans	27.00%	27.00%
Commercial and industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of PCI loans	47.00%	50.00%
Purchased Credit-Impaired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net of Deferred Income	$ 18,892,000	$ 20,143,000

X

- Definition

Percentage of Purchase Credit Impaired Loans.

+ References

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+ References

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- Definition

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524

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- Definition

The face amount of loans that will be sold to other entities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

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