Loans and Allowance for Loan Losses - Aggregated analysis of the changes in allowance for loan losses - (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Changes in allowance for loan losses
Balance at beginning of period	$ 43,890	$ 40,691	$ 40,355	$ 37,796
Loans charged-off	(1,658)	(1,388)	(5,137)	(5,194)
Recoveries of loans previously charged off	1,115	833	2,455	2,620
Net charge-offs	(543)	(555)	(2,682)	(2,574)
Provision (benefit)		912	8,082	6,175
Benefits attributable to FDIC loss share agreements net				23
Total provision for loan losses charged to operations	2,062	912	8,082	6,198
Provision for loan losses recorded through the FDIC loss share receivable				(23)
Reduction due to loan removals	(198)	(326)	(544)	(675)
Balance at end of period	45,211	40,722	45,211	40,722
Non-acquired loans
Changes in allowance for loan losses
Balance at beginning of period	40,149	36,939	36,960	34,090
Loans charged-off	(1,383)	(1,108)	(3,972)	(4,384)
Recoveries of loans previously charged off	836	713	2,041	2,358
Net charge-offs	(547)	(395)	(1,931)	(2,026)
Provision (benefit)		775	6,512	5,255
Total provision for loan losses charged to operations	1,939	775	6,512	5,255
Balance at end of period	41,541	37,319	41,541	37,319
Acquired non-credit impaired loans
Changes in allowance for loan losses
Loans charged-off	(275)	(280)	(1,165)	(810)
Recoveries of loans previously charged off	279	120	414	262
Net charge-offs	4	(160)	(751)	(548)
Provision (benefit)		160	751	548
Total provision for loan losses charged to operations	(4)	160	751	548
Acquired credit impaired loans
Changes in allowance for loan losses
Balance at beginning of period	3,741	3,752	3,395	3,706
Provision (benefit)	127	(23)	819	372
Benefits attributable to FDIC loss share agreements net				23
Benefits attributable to FDIC loss share agreements				23
Total provision for loan losses charged to operations	127	(23)	819	395
Provision for loan losses recorded through the FDIC loss share receivable				(23)
Reduction due to loan removals	(198)	(326)	(544)	(675)
Balance at end of period	3,670	3,403	3,670	3,403
Residential real estate \| Acquired credit impaired loans
Changes in allowance for loan losses
Provision (benefit)	184	2	743	(178)
Benefits attributable to FDIC loss share agreements				23
Total provision for loan losses charged to operations	184	2	743	(155)
Provision for loan losses recorded through the FDIC loss share receivable				(23)
Reduction due to loan removals	(149)	(102)	(386)	(316)
Commercial owner occupied real estate loan \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off		(16)
Recoveries of loans previously charged off	92	25
Total provision for loan losses charged to operations	479	516
Commercial owner occupied real estate loan \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Loans charged-off		(3)		(3)
Recoveries of loans previously charged off	1		1
Total provision for loan losses charged to operations	(1)	3	(1)	3
Consumer real estate \| Acquired credit impaired loans
Changes in allowance for loan losses
Provision (benefit)	(85)	(23)
Total provision for loan losses charged to operations	(85)	(23)
Reduction due to loan removals	(1)	(211)
Commercial and industrial \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off	(440)	(31)	(629)	(358)
Recoveries of loans previously charged off	31	104	264	207
Total provision for loan losses charged to operations	469	368	726	887
Commercial and industrial \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Loans charged-off	(1)	(23)	(3)	(30)
Recoveries of loans previously charged off	1	1	3	3
Total provision for loan losses charged to operations		22		27
Commercial and industrial \| Acquired credit impaired loans
Changes in allowance for loan losses
Provision (benefit)	(65)	(2)	71	38
Total provision for loan losses charged to operations	(65)	(2)	71	38
Reduction due to loan removals	(12)	(12)	(66)	(30)
Other income producing property \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off	(10)		(17)	(7)
Recoveries of loans previously charged off	29	8	77	47
Total provision for loan losses charged to operations	(10)	(201)	(214)	(384)
Other income producing property \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Recoveries of loans previously charged off			1	1
Total provision for loan losses charged to operations			(1)	(1)
Consumer \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off	(897)	(1,016)
Recoveries of loans previously charged off	168	216
Total provision for loan losses charged to operations	889	1,094
Consumer \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Loans charged-off	(123)	(149)	(337)	(485)
Recoveries of loans previously charged off	2	26	21	49
Total provision for loan losses charged to operations	121	123	316	436
Consumer \| Acquired credit impaired loans
Changes in allowance for loan losses
Provision (benefit)			(85)	511
Total provision for loan losses charged to operations			(85)	511
Reduction due to loan removals			(11)	(281)
Commercial \| Acquired credit impaired loans
Changes in allowance for loan losses
Provision (benefit)			(40)	1
Total provision for loan losses charged to operations			(40)	1
Reduction due to loan removals			(1)	(16)
Other loans \| Non-acquired loans
Changes in allowance for loan losses
Total provision for loan losses charged to operations	(114)	(521)
Construction and land development \| Commercial non-owner occupied real estate \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off	(19)
Recoveries of loans previously charged off	333	241
Total provision for loan losses charged to operations	(88)	(795)
Construction and land development \| Commercial non-owner occupied real estate \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Recoveries of loans previously charged off	1	1
Total provision for loan losses charged to operations	(1)	(1)
Construction and land development \| Commercial non-owner occupied real estate \| Acquired credit impaired loans
Changes in allowance for loan losses
Provision (benefit)	133
Total provision for loan losses charged to operations	133
Reduction due to loan removals	(36)	(6)
Construction and land development \| Commercial \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off			(493)	(159)
Recoveries of loans previously charged off			555	848
Total provision for loan losses charged to operations			1,819	(694)
Construction and land development \| Commercial \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Recoveries of loans previously charged off			3	3
Total provision for loan losses charged to operations			(3)	(3)
Construction and land development \| Commercial \| Acquired credit impaired loans
Changes in allowance for loan losses
Provision (benefit)			130
Total provision for loan losses charged to operations			130
Reduction due to loan removals			(80)	(32)
Other commercial non-owner occupied real estate \| Non-acquired loans
Changes in allowance for loan losses
Recoveries of loans previously charged off			128	59
Total provision for loan losses charged to operations			1,129	964
Other commercial non-owner occupied real estate \| Commercial non-owner occupied real estate \| Non-acquired loans
Changes in allowance for loan losses
Recoveries of loans previously charged off	80	28
Total provision for loan losses charged to operations	(7)	(93)
Other commercial non-owner occupied real estate \| Commercial non-owner occupied real estate \| Acquired credit impaired loans
Changes in allowance for loan losses
Provision (benefit)	(40)
Total provision for loan losses charged to operations	(40)
Reduction due to loan removals		5
Home equity loans \| Consumer real estate \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off	(17)
Recoveries of loans previously charged off	38	64
Total provision for loan losses charged to operations	(171)	69
Home equity loans \| Consumer real estate \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Loans charged-off	(71)	(105)
Recoveries of loans previously charged off	274	89
Total provision for loan losses charged to operations	(203)	16
Home equity loans \| Consumer \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off			(241)	(767)
Recoveries of loans previously charged off			133	239
Total provision for loan losses charged to operations			(6)	880
Home equity loans \| Consumer \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Loans charged-off			(736)	(292)
Recoveries of loans previously charged off			343	197
Total provision for loan losses charged to operations			393	95
Consumer \| Consumer \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off			(2,407)	(2,802)
Recoveries of loans previously charged off			546	787
Total provision for loan losses charged to operations			2,203	2,629
Other Consumer \| Consumer \| Non-acquired loans
Changes in allowance for loan losses
Total provision for loan losses charged to operations			(386)	28
Consumer Owner Occupied Loans \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off				(117)
Recoveries of loans previously charged off			197	46
Total provision for loan losses charged to operations			(109)	258
Consumer Owner Occupied Loans \| Consumer real estate \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off		(45)
Recoveries of loans previously charged off	65	27
Total provision for loan losses charged to operations	492	338
Consumer Owner Occupied Loans \| Consumer real estate \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Recoveries of loans previously charged off		3
Total provision for loan losses charged to operations	$ 80	$ (3)
Consumer Owner Occupied Loans \| Consumer \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off			(185)	(174)
Recoveries of loans previously charged off			141	125
Total provision for loan losses charged to operations			1,350	687
Consumer Owner Occupied Loans \| Consumer \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Loans charged-off			(89)
Recoveries of loans previously charged off			42	9
Total provision for loan losses charged to operations			$ 47	$ (9)

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Amount of change in the reserve, reduction(increase) for loan impairments as a result of current information and events which result in it being probable that estimated cash flows will be significantly higher than previously expected or because actual cash flows are significantly greater than cash flows previously expected for loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

No definition available.

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Provision for loan losses recorded through the FDIC loss share receivable - Amount of reduction in the reserve for loans impairments as a result of current information and events which result in it being probable that estimated cash flows will be significantly higher than previously expected or because actual cash flows are significantly greater than cash flows previously expected for loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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No definition available.

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- Definition

Reflects the amount of loans and leases that have been removed, or charged off, from both loan receivables and the reserve for credit losses, typically because they are considered to be not salvageable or have been purchased by unconsolidated collection entities. This amount is net of reduction in bad debt expense attributable to collections of loans and lease receivables which had previously been fully or partially charged off as bad debts.

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- Definition

The sum of the periodic provision charged to earnings before adjustment for amounts covered under loss sharing agreement.

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No definition available.

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

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The increase (decrease) in the allowance for credit losses related to financing receivables.

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- Definition

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

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of direct write-downs of financing receivables charged against the allowance.

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- Definition

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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