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, 2016	Sep. 30, 2015	Jun. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Changes in allowance for loan losses
Balance at beginning of period	$ 40,691	$ 39,470		$ 37,796	$ 41,904
Loans charged-off	(1,388)	(1,671)		(5,194)	(6,716)
Recoveries of loans previously charged off	833	928		2,620	2,576
Net charge-offs	(555)	(743)		(2,574)	(4,140)
Provision (benefit)	912	1,075		6,175	5,017
Benefits attributable to FDIC loss share agreements net				23	21
Total provision for loan losses charged to operations	912	1,075		6,198	5,038
Provision for loan losses recorded through the FDIC loss share receivable				23	(21)
Reduction due to loan removals	(326)	(212)		(675)	(3,191)
Balance at end of period	40,722	39,590	$ 39,470	40,722	39,590
Non-acquired loans
Changes in allowance for loan losses
Balance at beginning of period	36,939	34,782		34,090	34,539
Loans charged-off	(1,108)	(1,530)		(4,384)	(4,206)
Recoveries of loans previously charged off	713	655		2,358	2,253
Net charge-offs	(395)	(875)		(2,026)	(1,953)
Provision (benefit)	775	1,209		5,255	2,530
Total provision for loan losses charged to operations	775	1,209		5,255	2,530
Balance at end of period	37,319	35,116	34,782	37,319	35,116
Acquired credit impaired loans
Changes in allowance for loan losses
Balance at beginning of period	3,752	4,688		3,706	7,365
Balance at the beginning of the period	3,752	4,688		3,706
Provision (benefit)	(23)	(2)		372	300
Benefits attributable to FDIC loss share agreements net				23	21
Benefits attributable to FDIC loss share agreements					21
Total provision for loan losses charged to operations	(23)	(2)		395	321
Provision for loan losses recorded through the FDIC loss share receivable				23	(21)
Reduction due to loan removals	(326)	(212)		(675)	(3,191)
Balance at the end of the period	3,403	4,474	4,688	3,403	4,474
Balance at end of period	3,403	4,474	4,688	3,403	4,474
Acquired non-credit impaired loans
Changes in allowance for loan losses
Loans charged-off	(280)	(141)		(810)	(2,510)
Recoveries of loans previously charged off	120	273		262	323
Net charge-offs	(160)	132		(548)	(2,187)
Provision (benefit)	160	(132)		548	2,187
Total provision for loan losses charged to operations	160	(132)		548	2,187
Residential real estate \| Acquired credit impaired loans
Changes in allowance for loan losses
Balance at the beginning of the period	2,592	3,183
Provision (benefit)	2	(160)		(178)	(138)
Benefits attributable to FDIC loss share agreements net				23
Total provision for loan losses charged to operations	2	(160)		(155)	(138)
Provision for loan losses recorded through the FDIC loss share receivable				23
Reduction due to loan removals	(102)	(160)		(316)	(1,386)
Balance at the end of the period	2,492	2,863	3,183	2,492	2,863
Balance at end of period	2,492			2,492
Commercial non-owner occupied real estate \| Non-acquired loans \| Construction and land development
Changes in allowance for loan losses
Loans charged-off		(85)		(159)	(185)
Recoveries of loans previously charged off	241	122		848	256
Total provision for loan losses charged to operations	(795)	(826)		(694)	(1,528)
Commercial non-owner occupied real estate \| Non-acquired loans \| Other commercial non-owner occupied real estate
Changes in allowance for loan losses
Loans charged-off		(5)			(88)
Recoveries of loans previously charged off	28	23		59	52
Total provision for loan losses charged to operations	(93)	268		964	206
Commercial non-owner occupied real estate \| Acquired credit impaired loans \| Construction and land development
Changes in allowance for loan losses
Balance at the beginning of the period	151	344
Provision (benefit)		433			443
Total provision for loan losses charged to operations		433			443
Reduction due to loan removals	(6)	(49)		(32)	(51)
Balance at the end of the period	145	728	344	145	728
Balance at end of period	145			145
Commercial non-owner occupied real estate \| Acquired credit impaired loans \| Other commercial non-owner occupied real estate
Changes in allowance for loan losses
Balance at the beginning of the period	35	532
Provision (benefit)				1	3
Total provision for loan losses charged to operations				1	3
Reduction due to loan removals	5	(7)		(16)	(922)
Balance at the end of the period	40	525	532	40	525
Balance at end of period	41			41
Commercial non-owner occupied real estate \| Acquired non-credit impaired loans \| Construction and land development
Changes in allowance for loan losses
Recoveries of loans previously charged off	1	1		3	3
Total provision for loan losses charged to operations	(1)	(1)		(3)	(3)
Commercial owner occupied real estate loan \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off	(16)	(23)		(117)	(575)
Recoveries of loans previously charged off	25	7		46	23
Total provision for loan losses charged to operations	516	376		258	1,181
Commercial owner occupied real estate loan \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Loans charged-off	(3)			(3)
Total provision for loan losses charged to operations	3			3
Consumer real estate \| Non-acquired loans \| Home equity loans
Changes in allowance for loan losses
Loans charged-off		(74)		(767)	(282)
Recoveries of loans previously charged off	64	91		239	201
Total provision for loan losses charged to operations	69	26		880	163
Consumer real estate \| Acquired credit impaired loans
Changes in allowance for loan losses
Balance at the beginning of the period	778	449
Provision (benefit)	(23)	(249)		511	141
Benefits attributable to FDIC loss share agreements					(107)
Total provision for loan losses charged to operations	(23)	(249)		511	34
Provision for loan losses recorded through the FDIC loss share receivable					107
Reduction due to loan removals	(211)	(44)		(281)	(260)
Balance at the end of the period	544	156	449	544	156
Balance at end of period	543			543
Consumer real estate \| Acquired non-credit impaired loans \| Home equity loans
Changes in allowance for loan losses
Loans charged-off	(105)	(79)		(292)	(1,459)
Recoveries of loans previously charged off	89	161		197	178
Total provision for loan losses charged to operations	16	(82)		95	1,281
Commercial and industrial \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off	(31)	(102)		(358)	(357)
Recoveries of loans previously charged off	104	79		207	745
Total provision for loan losses charged to operations	368	16		887	27
Commercial and industrial \| Acquired credit impaired loans
Changes in allowance for loan losses
Balance at the beginning of the period	196	197
Provision (benefit)	(2)	15		38	(107)
Benefits attributable to FDIC loss share agreements					127
Total provision for loan losses charged to operations	(2)	15		38	20
Provision for loan losses recorded through the FDIC loss share receivable					(127)
Reduction due to loan removals	(12)	(12)		(30)	(411)
Balance at the end of the period	182	200	197	182	200
Balance at end of period	182			182
Commercial and industrial \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Loans charged-off	(23)	(7)		(30)	(120)
Recoveries of loans previously charged off	1	2		3	17
Total provision for loan losses charged to operations	22	5		27	103
Other income producing property \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off				(7)	(13)
Recoveries of loans previously charged off	8	11		47	77
Total provision for loan losses charged to operations	(201)	(3)		(384)	(269)
Other income producing property \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Loans charged-off					(3)
Recoveries of loans previously charged off		3		1	4
Total provision for loan losses charged to operations		(3)		(1)	(1)
Consumer \| Non-acquired loans
Changes in allowance for loan losses
Loans charged-off	(1,016)	(1,011)		(2,802)	(2,432)
Recoveries of loans previously charged off	216	233		787	765
Total provision for loan losses charged to operations	1,094	886		2,629	2,016
Consumer \| Acquired non-credit impaired loans
Changes in allowance for loan losses
Loans charged-off	(149)	(63)		(485)	(568)
Recoveries of loans previously charged off	26	11		49	21
Total provision for loan losses charged to operations	123	52		436	547
Single pay loans \| Acquired credit impaired loans
Changes in allowance for loan losses
Balance at the beginning of the period		49
Provision (benefit)		(48)			(49)
Benefits attributable to FDIC loss share agreements					1
Total provision for loan losses charged to operations		(48)			(48)
Provision for loan losses recorded through the FDIC loss share receivable					(1)
Reduction due to loan removals		1			(19)
Balance at the end of the period		2	49		2
Other loans \| Non-acquired loans
Changes in allowance for loan losses
Total provision for loan losses charged to operations	$ (521)	(5)		$ 28	5
Commercial loans 1000000 or more \| Acquired credit impaired loans
Changes in allowance for loan losses
Balance at the begining of period			$ (66)
Provision (benefit)		7			7
Total provision for loan losses charged to operations		7			7
Reduction due to loan removals		$ 59			$ (142)

Amount represents the benefits adjustment attributable to FDIC loss share agreements.

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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.

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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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- 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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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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Reserve for loans impairments recorded after acquisition as a result of current information and events which result in it being probable that estimated cash flows will be less than previously expected or because actual cash flows are less than cash flows previously expected. This relates to 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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=27045933&loc=d3e13503-111538

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

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

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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.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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