Loans and reserve for credit losses (Schedule of Accounts, Notes, Loans and Financing Receivable) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Commercial real estate:
Owner occupied	$ 259,109		$ 204,998
Non-owner occupied	497,543		347,014
Total commercial real estate loans	756,652		552,012
Construction	125,428		52,503
Residential real estate	204,687		101,557
Commercial and industrial	368,475		254,170
Consumer	37,298		35,990
Total loans	1,492,540		996,232
Less:
Deferred loan fees, net	(1,703)
Reserve for loan losses	(22,053)		(20,857)
Loans, net	1,468,784		973,618
Owner occupied, Percent	17.40%
Non-owner occupied, Percent	33.30%
Total commercial real estate loans, Percent	50.70%
Construction, Percent	8.40%
Residential real estate, Percent	13.70%
Commercial and industrial, Percent	24.70%
Consumer, Percent	2.50%
Total loans, percent	100.00%
Originated Loans, Receivable
Commercial real estate:
Owner occupied	198,845	[1]	204,998	[1]
Non-owner occupied	383,287	[1]	347,014	[1]
Total commercial real estate loans	582,132	[1]	552,012	[1]
Construction	100,437	[1]	52,503	[1]
Residential real estate	122,478	[1]	101,557	[1]
Commercial and industrial	342,746	[1]	254,170	[1]
Consumer	34,897	[1]	35,990	[1]
Total loans	1,182,690	[1]	996,232	[1]
Less:
Deferred loan fees, net	(1,703)	[1]	(1,757)	[1]
Reserve for loan losses	(22,053)	[1]	(20,857)	[1]
Loans, net	1,158,934	[1]	973,618	[1]
Owner occupied, Percent	16.80%	[1]	20.60%	[1]
Non-owner occupied, Percent	32.40%	[1]	34.80%	[1]
Total commercial real estate loans, Percent	49.20%	[1]	55.40%	[1]
Construction, Percent	8.50%	[1]	5.30%	[1]
Residential real estate, Percent	10.40%	[1]	10.20%	[1]
Commercial and industrial, Percent	29.00%	[1]	25.50%	[1]
Consumer, Percent	2.90%	[1]	3.60%	[1]
Total loans, percent	100.00%	[1]	100.00%	[1]
Acquired Loans, Receivable
Commercial real estate:
Owner occupied	48,413	[2]
Non-owner occupied	102,890	[2]
Total commercial real estate loans	151,303	[2]
Construction	22,564	[2]
Residential real estate	71,385	[2]
Commercial and industrial	22,444	[2]
Consumer	1,963	[2]
Total loans	269,659	[2]
Less:
Owner occupied, Percent	18.00%	[2]
Non-owner occupied, Percent	38.20%	[2]
Total commercial real estate loans, Percent	56.20%	[2]
Construction, Percent	8.40%	[2]
Residential real estate, Percent	26.50%	[2]
Commercial and industrial, Percent	8.30%	[2]
Consumer, Percent	0.60%	[2]
Total loans, percent	100.00%	[2]
Acquired Covered Loans, Receivable
Commercial real estate:
Owner occupied	11,851	[3]
Non-owner occupied	11,366	[3]
Total commercial real estate loans	23,217	[3]
Construction	2,427	[3]
Residential real estate	10,824	[3]
Commercial and industrial	3,285	[3]
Consumer	438	[3]
Total loans	$ 40,191	[3]
Less:
Owner occupied, Percent	29.50%	[3]
Non-owner occupied, Percent	28.30%	[3]
Total commercial real estate loans, Percent	57.80%	[3]
Construction, Percent	6.00%	[3]
Residential real estate, Percent	26.90%	[3]
Commercial and industrial, Percent	8.20%	[3]
Consumer, Percent	1.10%	[3]
Total loans, percent	100.00%	[3]

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

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

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