Loans - Summary of Allowance for Loan Losses by Portfolio Class and Category (Details) $ in Thousands	3 Months Ended
Mar. 31, 2019 USD ($)
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2018	$ 43,476
Balance	43,095
Portfolio loans, net
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2018	42,295
Provision (provision reversal) for loan losses	1,476
Losses charged off	(2,250)
Recoveries	424
Balance	41,945
Portfolio loans, net \| Commercial and industrial
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2018	29,039
Provision (provision reversal) for loan losses	1,445
Losses charged off	(1,853)
Recoveries	29
Balance	28,660
Portfolio loans, net \| CRE - investor owned
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2018	4,683
Provision (provision reversal) for loan losses	769
Losses charged off	(120)
Recoveries	7
Balance	5,339
Portfolio loans, net \| CRE - owner occupied
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2018	4,239
Provision (provision reversal) for loan losses	(431)
Losses charged off	(36)
Recoveries	2
Balance	3,774
Portfolio loans, net \| Construction and land development
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2018	1,987
Provision (provision reversal) for loan losses	(252)
Losses charged off	(45)
Recoveries	9
Balance	1,699
Portfolio loans, net \| Residential real estate
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2018	1,616
Provision (provision reversal) for loan losses	(288)
Losses charged off	(67)
Recoveries	364
Balance	1,625
Portfolio loans, net \| Consumer and other
Allowance for Loan Losses [Roll Forward]
Balance at December 31, 2018	731
Provision (provision reversal) for loan losses	233
Losses charged off	(129)
Recoveries	13
Balance	$ 848

A valuation allowance for financing receivables that are expected to be uncollectible.

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No definition available.

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Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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