Loans - (Loan Delinquency) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Loans [Line Items]
Total loans	$ 2,738,504	$ 2,587,673	$ 2,328,524
Commercial Loan [Member]
Loans [Line Items]
Total loans	1,490,749	1,427,420
Commercial Real Estate [Member]
Loans [Line Items]
Total loans	525,739	442,885
Residential Real Estate Segment [Member]
Loans [Line Items]
Total loans	694,171	684,002
Consumer [Member]
Loans [Line Items]
Total loans	27,845	33,366
Non ASC 310-30 [Member]
Loans [Line Items]
Total loans	2,569,222	2,384,843
Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total loans	1,443,874	1,369,946
Non ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total loans	424,020	321,712
Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total loans	674,830	662,550
Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total loans	26,498	30,635
ASC 310-30 [Member]
Loans [Line Items]
Total loans	169,282	202,830
ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total loans	46,875	57,474
ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total loans	101,719	121,173
ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total loans	19,341	21,452
ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total loans	1,347	2,731
Total Loans [Member]
Loans [Line Items]
Total loans	2,738,504	2,587,673
Total Loans [Member] | Non ASC 310-30 [Member]
Loans [Line Items]
Total past due	23,444	20,042
Current	2,545,778	2,364,801
Total loans	2,569,222	2,384,843
Loans 90 days past due and still accruing	43	166
Non- accrual	37,428	25,647
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Construction [Member]
Loans [Line Items]
Total past due	314	547
Current	82,822	29,596
Total loans	83,136	30,143
Loans 90 days past due and still accruing	38
Non- accrual		188
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Acquisition/Development [Member]
Loans [Line Items]
Total past due	739
Current	8,024	5,575
Total loans	8,763	5,575
Total Loans [Member] | Non ASC 310-30 [Member] | Multifamily [Member]
Loans [Line Items]
Total past due		60
Current	10,811	9,813
Total loans	10,811	9,873
Non- accrual		22
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial and Industrial [Member]
Loans [Line Items]
Total past due	3,304	2,539
Current	1,012,554	890,350
Total loans	1,015,858	892,889
Non- accrual	4,289	4,830
Total Loans [Member] | Non ASC 310-30 [Member] | Owner-Occupied [Member]
Loans [Line Items]
Total past due	1,286	547
Current	190,382	184,072
Total loans	191,668	184,619
Non- accrual	906	1,273
Total Loans [Member] | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]
Loans [Line Items]
Total past due	747	3,490
Current	320,563	272,631
Total loans	321,310	276,121
Non- accrual	71	1,013
Total Loans [Member] | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]
Loans [Line Items]
Total past due	1,800	4,097
Current	422,220	317,615
Total loans	424,020	321,712
Loans 90 days past due and still accruing	38
Non- accrual	71	1,223
Total Loans [Member] | Non ASC 310-30 [Member] | Senior lien
Loans [Line Items]
Total past due	2,986	4,301
Current	617,771	610,192
Total loans	620,757	614,493
Loans 90 days past due and still accruing		124
Non- accrual	3,449	3,713
Total Loans [Member] | Non ASC 310-30 [Member] | Junior lien
Loans [Line Items]
Total past due	535	730
Current	53,538	47,327
Total loans	54,073	48,057
Loans 90 days past due and still accruing	5	6
Non- accrual	781	584
Total Loans [Member] | Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total past due	18,069	10,611
Current	1,425,805	1,359,335
Total loans	1,443,874	1,369,946
Non- accrual	32,897	20,095
Total Loans [Member] | Non ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total past due	1,257	1,721
Current	130,428	143,837
Total loans	131,685	145,558
Non- accrual	1,852	1,984
Total Loans [Member] | Non ASC 310-30 [Member] | Energy Loans [Member]
Loans [Line Items]
Total past due	12,222	5,804
Current	92,441	141,076
Total loans	104,663	146,880
Non- accrual	25,850	12,008
Total Loans [Member] | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total past due	3,521	5,031
Current	671,309	657,519
Total loans	674,830	662,550
Loans 90 days past due and still accruing	5	130
Non- accrual	4,230	4,297
Total Loans [Member] | Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total past due	54	303
Current	26,444	30,332
Total loans	26,498	30,635
Loans 90 days past due and still accruing		36
Non- accrual	230	32
Total Loans [Member] | ASC 310-30 [Member]
Loans [Line Items]
Total loans	169,282	202,830
Total Loans [Member] | ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total loans	46,875	57,474
Total Loans [Member] | ASC 310-30 [Member] | Commercial Real Estate [Member]
Loans [Line Items]
Total loans	101,719	121,173
Total Loans [Member] | ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total loans	19,341	21,452
Total Loans [Member] | ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total loans	1,347	2,731
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member]
Loans [Line Items]
Total past due	4,274	8,232
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member] | Commercial Construction [Member]
Loans [Line Items]
Total past due	277	359
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member] | Commercial and Industrial [Member]
Loans [Line Items]
Total past due	168	2,252
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member] | Owner-Occupied [Member]
Loans [Line Items]
Total past due	859	370
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]
Loans [Line Items]
Total past due	718	2,340
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]
Loans [Line Items]
Total past due	995	2,699
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member] | Senior lien
Loans [Line Items]
Total past due	1,780	1,909
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member] | Junior lien
Loans [Line Items]
Total past due	345	299
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total past due	1,140	3,086
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total past due	19	441
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member] | Energy Loans [Member]
Loans [Line Items]
Total past due	94	23
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total past due	2,125	2,208
Total Loans [Member] | 30-59 Days Past Due | Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total past due	14	239
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member]
Loans [Line Items]
Total past due	1,467	7,770
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Commercial Construction [Member]
Loans [Line Items]
Total past due		188
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Commercial Acquisition/Development [Member]
Loans [Line Items]
Total past due	739
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Multifamily [Member]
Loans [Line Items]
Total past due		38
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Commercial and Industrial [Member]
Loans [Line Items]
Total past due	18	238
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Owner-Occupied [Member]
Loans [Line Items]
Total past due		111
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]
Loans [Line Items]
Total past due		182
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]
Loans [Line Items]
Total past due	739	408
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Senior lien
Loans [Line Items]
Total past due	623	911
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Junior lien
Loans [Line Items]
Total past due	47	237
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total past due	18	6,188
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total past due		58
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Energy Loans [Member]
Loans [Line Items]
Total past due		5,781
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total past due	670	1,148
Total Loans [Member] | 60-89 Days Past Due | Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total past due	40	26
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member]
Loans [Line Items]
Total past due	17,703	4,040
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Commercial Construction [Member]
Loans [Line Items]
Total past due	37
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Multifamily [Member]
Loans [Line Items]
Total past due		22
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Commercial and Industrial [Member]
Loans [Line Items]
Total past due	3,118	49
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Owner-Occupied [Member]
Loans [Line Items]
Total past due	427	66
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Non Owner-Occupied [Member]
Loans [Line Items]
Total past due	29	968
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Total Commercial Real Estate [Member]
Loans [Line Items]
Total past due	66	990
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Senior lien
Loans [Line Items]
Total past due	583	1,481
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Junior lien
Loans [Line Items]
Total past due	143	194
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Commercial Loan [Member]
Loans [Line Items]
Total past due	16,911	1,337
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Agriculture [Member]
Loans [Line Items]
Total past due	1,238	1,222
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Energy Loans [Member]
Loans [Line Items]
Total past due	12,128
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Residential Real Estate Segment [Member]
Loans [Line Items]
Total past due	726	1,675
Total Loans [Member] | Greater than 90 Days Past Due | Non ASC 310-30 [Member] | Consumer [Member]
Loans [Line Items]
Total past due		38
Non Accrual [Member]
Loans [Line Items]
Non- accrual	$ 37,400	$ 25,600