Loans and reserve for credit losses (Financing Receivable Credit Quality Indicators) (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Commercial real estate:
Owner occupied		$ 327,735	$ 259,109
Non-owner occupied		494,376	497,543
Loans Receivable, Gross, Commercial, Real Estate		822,111	756,652
Loans Receivable, Gross, Commercial, Construction		135,276	125,428
Loans and Leases Receivable, Gross, Consumer, Real Estate		255,061	204,687
Loans Receivable, Gross, Commercial and Industrial		375,207	368,475
Loans and Leases Receivable, Gross, Consumer		38,935	37,298
Loans and Leases Receivable, gross		1,626,590	1,492,540
Acceptable
Commercial real estate:
Owner occupied		289,076	220,545
Non-owner occupied		441,396	431,428
Loans Receivable, Gross, Commercial, Real Estate		730,472	651,973
Loans Receivable, Gross, Commercial, Construction		130,876	117,936
Loans and Leases Receivable, Gross, Consumer, Real Estate		251,638	198,883
Loans Receivable, Gross, Commercial and Industrial		338,044	331,045
Loans and Leases Receivable, Gross, Consumer		38,918	37,197
Loans and Leases Receivable, gross		1,489,948	1,337,034
Pass-Watch
Commercial real estate:
Owner occupied		13,518	9,874
Non-owner occupied		18,914	21,763
Loans Receivable, Gross, Commercial, Real Estate		32,432	31,637
Loans Receivable, Gross, Commercial, Construction		2,958	5,418
Loans and Leases Receivable, Gross, Consumer, Real Estate		869	1,380
Loans Receivable, Gross, Commercial and Industrial		20,029	18,872
Loans and Leases Receivable, Gross, Consumer		0	0
Loans and Leases Receivable, gross		56,288	57,307
Special Mention
Commercial real estate:
Owner occupied		10,305	9,435
Non-owner occupied		20,270	33,051
Loans Receivable, Gross, Commercial, Real Estate		30,575	42,486
Loans Receivable, Gross, Commercial, Construction		1,383	1,850
Loans and Leases Receivable, Gross, Consumer, Real Estate		601	552
Loans Receivable, Gross, Commercial and Industrial		3,594	14,676
Loans and Leases Receivable, Gross, Consumer		0	0
Loans and Leases Receivable, gross		36,153	59,564
Substandard
Commercial real estate:
Owner occupied		14,836	19,255
Non-owner occupied		13,796	11,301
Loans Receivable, Gross, Commercial, Real Estate		28,632	30,556
Loans Receivable, Gross, Commercial, Construction		59	224
Loans and Leases Receivable, Gross, Consumer, Real Estate		1,953	3,872
Loans Receivable, Gross, Commercial and Industrial		13,540	3,882
Loans and Leases Receivable, Gross, Consumer		17	101
Loans and Leases Receivable, gross		44,201	38,635
Originated Loans
Commercial real estate:
Owner occupied	[1],[2]	271,263	198,845
Non-owner occupied	[1],[2]	394,516	383,287
Loans Receivable, Gross, Commercial, Real Estate	[1],[2]	665,779	582,132
Loans Receivable, Gross, Commercial, Construction	[1],[2]	120,706	100,437
Loans and Leases Receivable, Gross, Consumer, Real Estate	[1],[2]	184,309	122,478
Loans Receivable, Gross, Commercial and Industrial	[1],[2]	352,189	342,746
Loans and Leases Receivable, Gross, Consumer	[1],[2]	37,129	34,897
Loans and Leases Receivable, gross	[1],[2],[3]	1,360,112	1,182,690
Originated Loans | Acceptable
Commercial real estate:
Owner occupied	[1]	244,397	167,509
Non-owner occupied	[1]	368,635	350,420
Loans Receivable, Gross, Commercial, Real Estate	[1]	613,032	517,929
Loans Receivable, Gross, Commercial, Construction	[1]	118,485	95,440
Loans and Leases Receivable, Gross, Consumer, Real Estate	[1]	182,320	119,280
Loans Receivable, Gross, Commercial and Industrial	[1]	319,169	306,030
Loans and Leases Receivable, Gross, Consumer	[1]	37,116	34,852
Loans and Leases Receivable, gross	[1]	1,270,122	1,073,531
Originated Loans | Pass-Watch
Commercial real estate:
Owner occupied	[1]	9,972	8,749
Non-owner occupied	[1]	12,614	10,383
Loans Receivable, Gross, Commercial, Real Estate	[1]	22,586	19,132
Loans Receivable, Gross, Commercial, Construction	[1]	818	3,086
Loans and Leases Receivable, Gross, Consumer, Real Estate	[1]	869	1,380
Loans Receivable, Gross, Commercial and Industrial	[1]	19,922	18,721
Loans and Leases Receivable, Gross, Consumer	[1]	0	0
Loans and Leases Receivable, gross	[1]	44,195	42,319
Originated Loans | Special Mention
Commercial real estate:
Owner occupied	[1]	2,419	4,035
Non-owner occupied	[1]	7,768	16,145
Loans Receivable, Gross, Commercial, Real Estate	[1]	10,187	20,180
Loans Receivable, Gross, Commercial, Construction	[1]	1,383	1,850
Loans and Leases Receivable, Gross, Consumer, Real Estate	[1]	601	552
Loans Receivable, Gross, Commercial and Industrial	[1]	70	14,676
Loans and Leases Receivable, Gross, Consumer	[1]	0	0
Loans and Leases Receivable, gross	[1]	12,241	37,258
Originated Loans | Substandard
Commercial real estate:
Owner occupied	[1]	14,475	18,552
Non-owner occupied	[1]	5,499	6,339
Loans Receivable, Gross, Commercial, Real Estate	[1]	19,974	24,891
Loans Receivable, Gross, Commercial, Construction	[1]	20	61
Loans and Leases Receivable, Gross, Consumer, Real Estate	[1]	519	1,266
Loans Receivable, Gross, Commercial and Industrial	[1]	13,028	3,319
Loans and Leases Receivable, Gross, Consumer	[1]	13	45
Loans and Leases Receivable, gross	[1]	33,554	29,582
Acquired Loans
Commercial real estate:
Owner occupied	[4],[5]	45,469	48,413
Non-owner occupied	[4],[5]	89,522	102,890
Loans Receivable, Gross, Commercial, Real Estate	[4],[5]	134,991	151,303
Loans Receivable, Gross, Commercial, Construction	[4],[5]	12,346	22,564
Loans and Leases Receivable, Gross, Consumer, Real Estate	[4],[5]	61,773	71,385
Loans Receivable, Gross, Commercial and Industrial	[4],[5]	20,592	22,444
Loans and Leases Receivable, Gross, Consumer	[4],[5]	1,491	1,963
Loans and Leases Receivable, gross	[4],[5],[6]	231,193	269,659
Acquired Loans | Acceptable
Commercial real estate:
Owner occupied	[5]	33,779	42,673
Non-owner occupied	[5]	67,634	75,340
Loans Receivable, Gross, Commercial, Real Estate	[5]	101,413	118,013
Loans Receivable, Gross, Commercial, Construction	[5]	12,346	22,448
Loans and Leases Receivable, Gross, Consumer, Real Estate	[5]	60,686	70,002
Loans Receivable, Gross, Commercial and Industrial	[5]	16,952	22,236
Loans and Leases Receivable, Gross, Consumer	[5]	1,487	1,907
Loans and Leases Receivable, gross	[5]	192,884	234,606
Acquired Loans | Pass-Watch
Commercial real estate:
Owner occupied	[5]	3,546	1,125
Non-owner occupied	[5]	6,300	11,019
Loans Receivable, Gross, Commercial, Real Estate	[5]	9,846	12,144
Loans Receivable, Gross, Commercial, Construction	[5]	0	0
Loans and Leases Receivable, Gross, Consumer, Real Estate	[5]	0	0
Loans Receivable, Gross, Commercial and Industrial	[5]	107	151
Loans and Leases Receivable, Gross, Consumer	[5]	0	0
Loans and Leases Receivable, gross	[5]	9,953	12,295
Acquired Loans | Special Mention
Commercial real estate:
Owner occupied	[5]	7,886	4,352
Non-owner occupied	[5]	7,909	12,265
Loans Receivable, Gross, Commercial, Real Estate	[5]	15,795	16,617
Loans Receivable, Gross, Commercial, Construction	[5]	0	0
Loans and Leases Receivable, Gross, Consumer, Real Estate	[5]	0	0
Loans Receivable, Gross, Commercial and Industrial	[5]	3,524	0
Loans and Leases Receivable, Gross, Consumer	[5]	0	0
Loans and Leases Receivable, gross	[5]	19,319	16,617
Acquired Loans | Substandard
Commercial real estate:
Owner occupied	[5]	258	263
Non-owner occupied	[5]	7,679	4,266
Loans Receivable, Gross, Commercial, Real Estate	[5]	7,937	4,529
Loans Receivable, Gross, Commercial, Construction	[5]	0	116
Loans and Leases Receivable, Gross, Consumer, Real Estate	[5]	1,087	1,383
Loans Receivable, Gross, Commercial and Industrial	[5]	9	57
Loans and Leases Receivable, Gross, Consumer	[5]	4	56
Loans and Leases Receivable, gross	[5]	9,037	6,141
Acquired Covered Loans
Commercial real estate:
Owner occupied	[7],[8]	11,003	11,851
Non-owner occupied	[7],[8]	10,338	11,366
Loans Receivable, Gross, Commercial, Real Estate	[7],[8]	21,341	23,217
Loans Receivable, Gross, Commercial, Construction	[7],[8]	2,224	2,427
Loans and Leases Receivable, Gross, Consumer, Real Estate	[7],[8]	8,979	10,824
Loans Receivable, Gross, Commercial and Industrial	[7],[8]	2,426	3,285
Loans and Leases Receivable, Gross, Consumer	[7],[8]	315	438
Loans and Leases Receivable, gross	[7],[8],[9]	35,285	40,191
Acquired Covered Loans | Acceptable
Commercial real estate:
Owner occupied	[8]	10,900	10,363
Non-owner occupied	[8]	5,127	5,668
Loans Receivable, Gross, Commercial, Real Estate	[8]	16,027	16,031
Loans Receivable, Gross, Commercial, Construction	[8]	45	48
Loans and Leases Receivable, Gross, Consumer, Real Estate	[8]	8,632	9,601
Loans Receivable, Gross, Commercial and Industrial	[8]	1,923	2,779
Loans and Leases Receivable, Gross, Consumer	[8]	315	438
Loans and Leases Receivable, gross	[8]	26,942	28,897
Acquired Covered Loans | Pass-Watch
Commercial real estate:
Owner occupied	[8]	0	0
Non-owner occupied	[8]	0	361
Loans Receivable, Gross, Commercial, Real Estate	[8]	0	361
Loans Receivable, Gross, Commercial, Construction	[8]	2,140	2,332
Loans and Leases Receivable, Gross, Consumer, Real Estate	[8]	0	0
Loans Receivable, Gross, Commercial and Industrial	[8]	0	0
Loans and Leases Receivable, Gross, Consumer	[8]	0	0
Loans and Leases Receivable, gross	[8]	2,140	2,693
Acquired Covered Loans | Special Mention
Commercial real estate:
Owner occupied	[8]	0	1,048
Non-owner occupied	[8]	4,593	4,641
Loans Receivable, Gross, Commercial, Real Estate	[8]	4,593	5,689
Loans Receivable, Gross, Commercial, Construction	[8]	0	0
Loans and Leases Receivable, Gross, Consumer, Real Estate	[8]	0	0
Loans Receivable, Gross, Commercial and Industrial	[8]	0	0
Loans and Leases Receivable, Gross, Consumer	[8]	0	0
Loans and Leases Receivable, gross	[8]	4,593	5,689
Acquired Covered Loans | Substandard
Commercial real estate:
Owner occupied	[8]	103	440
Non-owner occupied	[8]	618	696
Loans Receivable, Gross, Commercial, Real Estate	[8]	721	1,136
Loans Receivable, Gross, Commercial, Construction	[8]	39	47
Loans and Leases Receivable, Gross, Consumer, Real Estate	[8]	347	1,223
Loans Receivable, Gross, Commercial and Industrial	[8]	503	506
Loans and Leases Receivable, Gross, Consumer	[8]	0	0
Loans and Leases Receivable, gross	[8]	$ 1,610	$ 2,912

[1] Originated loans are loans organically made through the Company's normal and customary origination process

[2] Originated loans are loans organically made through the Company's normal and customary origination process, including ARM purchases

[3] Originated loans are loans organically made through the Company's normal and customary origination process

[4] Acquired loans are loans acquired in the acquisition of Home Federal Bancorp, Inc. ("Home"), discussed elsewhere in this Quarterly Report on Form 10-Q (the "Form 10-Q"), less acquired covered loans.

[5] Acquired loans are loans acquired in the acquisition of Home less acquired covered loans.

[6] Acquired loans are loans acquired in the acquisition of Home less acquired covered loans.

[7] Acquired covered loans are loans acquired in the acquisition of Home that are covered under FDIC loss share agreements.

[8] Acquired covered loans are loans in the Home portfolio that are covered under FDIC loss share agreements

[9] Acquired covered loans acquired in the acquisition of Home that are covered under FDIC loss share agreements