Loans and reserve for credit losses (Past Due Financing Receivables) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	$ 3,398		$ 2,260
90 days or more past due	5,282		5,270
Total past due	8,680		7,530
Current	1,386,248		988,702
Total loans	1,394,928		996,232
Commercial Real Estate Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	250		959
90 days or more past due	2,696		2,905
Total past due	2,946		3,864
Current	253,116		201,134
Total loans	256,062		204,998
Commercial Real Estate Non Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	222		0
90 days or more past due	359		0
Total past due	581		0
Current	495,540		347,014
Total loans	496,121		347,014
Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	472		959
90 days or more past due	3,055		2,905
Total past due	3,527		3,864
Current	748,656		548,148
Total loans	752,183		552,012
Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	0		215
90 days or more past due	746		119
Total past due	746		334
Current	104,265		52,169
Total loans	105,011		52,503
Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	1,889		436
90 days or more past due	747		163
Total past due	2,636		599
Current	196,243		100,958
Total loans	198,879		101,557
Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	809		597
90 days or more past due	715		2,077
Total past due	1,524		2,674
Current	299,209		251,496
Total loans	300,733		254,170
Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	228		53
90 days or more past due	19		6
Total past due	247		59
Current	37,875		35,931
Total loans	38,122		35,990
Originated Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	1,760	[1]
90 days or more past due	4,594	[1]
Total past due	6,354	[1]
Current	1,010,304	[1]
Total loans	1,016,658	[1]	996,232	[1]
Originated Loans | Commercial Real Estate Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	250	[1]
90 days or more past due	2,612	[1]
Total past due	2,862	[1]
Current	187,850	[1]
Total loans	190,712	[1]
Originated Loans | Commercial Real Estate Non Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	222	[1]
90 days or more past due	332	[1]
Total past due	554	[1]
Current	365,273	[1]
Total loans	365,827	[1]
Originated Loans | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	472	[1]
90 days or more past due	2,944	[1]
Total past due	3,416	[1]
Current	553,123	[1]
Total loans	556,539	[1]
Originated Loans | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	0	[1]
90 days or more past due	746	[1]
Total past due	746	[1]
Current	53,574	[1]
Total loans	54,320	[1]
Originated Loans | Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	326	[1]
90 days or more past due	220	[1]
Total past due	546	[1]
Current	101,429	[1]
Total loans	101,975	[1]
Originated Loans | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	805	[1]
90 days or more past due	665	[1]
Total past due	1,470	[1]
Current	267,549	[1]
Total loans	269,019	[1]
Originated Loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	157	[1]
90 days or more past due	19	[1]
Total past due	176	[1]
Current	34,629	[1]
Total loans	34,805	[1]
Acquired Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	1,338	[2]
90 days or more past due	527	[2]
Total past due	1,865	[2]
Current	322,805	[2]
Total loans	324,670	[2],[3]
Acquired Loans | Commercial Real Estate Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	0	[2]
90 days or more past due	0	[2]
Total past due	0	[2]
Current	52,267	[2]
Total loans	52,267	[2]
Acquired Loans | Commercial Real Estate Non Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	0	[2]
90 days or more past due	0	[2]
Total past due	0	[2]
Current	110,650	[2]
Total loans	110,650	[2]
Acquired Loans | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	0	[2]
90 days or more past due	0	[2]
Total past due	0	[2]
Current	162,917	[2]
Total loans	162,917	[2]
Acquired Loans | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	0	[2]
90 days or more past due	0	[2]
Total past due	0	[2]
Current	48,127	[2]
Total loans	48,127	[2]
Acquired Loans | Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	1,285	[2]
90 days or more past due	527	[2]
Total past due	1,812	[2]
Current	81,964	[2]
Total loans	83,776	[2]
Acquired Loans | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	4	[2]
90 days or more past due	0	[2]
Total past due	4	[2]
Current	27,089	[2]
Total loans	27,093	[2]
Acquired Loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	49	[2]
90 days or more past due	0	[2]
Total past due	49	[2]
Current	2,708	[2]
Total loans	2,757	[2]
Acquired Covered Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	300	[4]
90 days or more past due	161	[4]
Total past due	461	[4]
Current	53,139	[4]
Total loans	53,600	[4],[5]
Acquired Covered Loans | Commercial Real Estate Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	0	[4]
90 days or more past due	84	[4]
Total past due	84	[4]
Current	12,999	[4]
Total loans	13,083	[4]
Acquired Covered Loans | Commercial Real Estate Non Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	0	[4]
90 days or more past due	27	[4]
Total past due	27	[4]
Current	19,617	[4]
Total loans	19,644	[4]
Acquired Covered Loans | Commercial Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	0	[4]
90 days or more past due	111	[4]
Total past due	111	[4]
Current	32,616	[4]
Total loans	32,727	[4]
Acquired Covered Loans | Construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	0	[4]
90 days or more past due	0	[4]
Total past due	0	[4]
Current	2,564	[4]
Total loans	2,564	[4]
Acquired Covered Loans | Residential real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	278	[4]
90 days or more past due	0	[4]
Total past due	278	[4]
Current	12,850	[4]
Total loans	13,128	[4]
Acquired Covered Loans | Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	0	[4]
90 days or more past due	50	[4]
Total past due	50	[4]
Current	4,571	[4]
Total loans	4,621	[4]
Acquired Covered Loans | Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-89 days past due	22	[4]
90 days or more past due	0	[4]
Total past due	22	[4]
Current	538	[4]
Total loans	$ 560	[4]

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

[2] Acquired loans are loans acquired in the acquisition of Home, discussed elsewhere in this report, less acquired covered loans

[3] Acquired loans are loans acquired in the acquisition of Home, discussed elsewhere in this report

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

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