Loans and reserve for credit losses (Past Due Financing Receivables) (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due		$ 1,638	$ 5,365
90 days or more past due		1,969	5,711
Total past due		3,607	11,076
Current		1,622,983	1,481,464
Total loans		1,626,590	1,492,540
Commercial Real Estate Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due		185	756
90 days or more past due		1,215	3,716
Total past due		1,400	4,472
Current		326,335	254,637
Total loans		327,735	259,109
Commercial Real Estate Non Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due		0	1,718
90 days or more past due		0	1,118
Total past due		0	2,836
Current		494,376	494,707
Total loans		494,376	497,543
Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due		185	2,474
90 days or more past due		1,215	4,834
Total past due		1,400	7,308
Current		820,711	749,344
Total loans		822,111	756,652
Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due		0	0
90 days or more past due		0	100
Total past due		0	100
Current		135,276	125,328
Total loans		135,276	125,428
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due		1,109	2,398
90 days or more past due		351	398
Total past due		1,460	2,796
Current		253,601	201,891
Total loans		255,061	204,687
Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due		159	288
90 days or more past due		390	334
Total past due		549	622
Current		374,658	367,853
Total loans		375,207	368,475
Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due		185	205
90 days or more past due		13	45
Total past due		198	250
Current		38,737	37,048
Total loans		38,935	37,298
Originated Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[1]	512	3,539
90 days or more past due	[1]	1,613	5,276
Total past due	[1]	2,125	8,815
Current	[1]	1,357,987	1,173,875
Total loans	[1],[2],[3]	1,360,112	1,182,690
Originated Loans | Commercial Real Estate Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[1]	0	732
90 days or more past due	[1]	1,215	3,716
Total past due	[1]	1,215	4,448
Current	[1]	270,048	194,397
Total loans	[1]	271,263	198,845
Originated Loans | Commercial Real Estate Non Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[1]	0	1,718
90 days or more past due	[1]	0	971
Total past due	[1]	0	2,689
Current	[1]	394,516	380,598
Total loans	[1]	394,516	383,287
Originated Loans | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[1]	0	2,450
90 days or more past due	[1]	1,215	4,687
Total past due	[1]	1,215	7,137
Current	[1]	664,564	574,995
Total loans	[1]	665,779	582,132
Originated Loans | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[1]	0	0
90 days or more past due	[1]	0	100
Total past due	[1]	0	100
Current	[1]	120,706	100,337
Total loans	[1]	120,706	100,437
Originated Loans | Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[1]	181	662
90 days or more past due	[1]	0	110
Total past due	[1]	181	772
Current	[1]	184,128	121,706
Total loans	[1]	184,309	122,478
Originated Loans | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[1]	159	288
90 days or more past due	[1]	385	334
Total past due	[1]	544	622
Current	[1]	351,645	342,124
Total loans	[1]	352,189	342,746
Originated Loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[1]	172	139
90 days or more past due	[1]	13	45
Total past due	[1]	185	184
Current	[1]	36,944	34,713
Total loans	[1]	37,129	34,897
Acquired Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[4]	627	1,440
90 days or more past due	[4]	351	408
Total past due	[4]	978	1,848
Current	[4]	230,215	267,811
Total loans	[4],[5],[6]	231,193	269,659
Acquired Loans | Commercial Real Estate Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[4]	0	24
90 days or more past due	[4]	0	0
Total past due	[4]	0	24
Current	[4]	45,469	48,389
Total loans	[4]	45,469	48,413
Acquired Loans | Commercial Real Estate Non Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[4]	0	0
90 days or more past due	[4]	0	120
Total past due	[4]	0	120
Current	[4]	89,522	102,770
Total loans	[4]	89,522	102,890
Acquired Loans | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[4]	0	24
90 days or more past due	[4]	0	120
Total past due	[4]	0	144
Current	[4]	134,991	151,159
Total loans	[4]	134,991	151,303
Acquired Loans | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[4]	0	0
90 days or more past due	[4]	0	0
Total past due	[4]	0	0
Current	[4]	12,346	22,564
Total loans	[4]	12,346	22,564
Acquired Loans | Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[4]	614	1,361
90 days or more past due	[4]	351	288
Total past due	[4]	965	1,649
Current	[4]	60,808	69,736
Total loans	[4]	61,773	71,385
Acquired Loans | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[4]	0	0
90 days or more past due	[4]	0	0
Total past due	[4]	0	0
Current	[4]	20,592	22,444
Total loans	[4]	20,592	22,444
Acquired Loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[4]	13	55
90 days or more past due	[4]	0	0
Total past due	[4]	13	55
Current	[4]	1,478	1,908
Total loans	[4]	1,491	1,963
Acquired Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[7]	499	386
90 days or more past due	[7]	5	27
Total past due	[7]	504	413
Current	[7]	34,781	39,778
Total loans	[7],[8],[9]	35,285	40,191
Acquired Covered Loans | Commercial Real Estate Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[7]	185	0
90 days or more past due	[7]	0	0
Total past due	[7]	185	0
Current	[7]	10,818	11,851
Total loans	[7]	11,003	11,851
Acquired Covered Loans | Commercial Real Estate Non Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[7]	0	0
90 days or more past due	[7]	0	27
Total past due	[7]	0	27
Current	[7]	10,338	11,339
Total loans	[7]	10,338	11,366
Acquired Covered Loans | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[7]	185	0
90 days or more past due	[7]	0	27
Total past due	[7]	185	27
Current	[7]	21,156	23,190
Total loans	[7]	21,341	23,217
Acquired Covered Loans | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[7]	0	0
90 days or more past due	[7]	0	0
Total past due	[7]	0	0
Current	[7]	2,224	2,427
Total loans	[7]	2,224	2,427
Acquired Covered Loans | Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[7]	314	375
90 days or more past due	[7]	0	0
Total past due	[7]	314	375
Current	[7]	8,665	10,449
Total loans	[7]	8,979	10,824
Acquired Covered Loans | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[7]	0	0
90 days or more past due	[7]	5	0
Total past due	[7]	5	0
Current	[7]	2,421	3,285
Total loans	[7]	2,426	3,285
Acquired Covered Loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	[7]	0	11
90 days or more past due	[7]	0	0
Total past due	[7]	0	11
Current	[7]	315	427
Total loans	[7]	$ 315	$ 438

[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

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

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

[5] 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.

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

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

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

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