Loans (Details 7) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Credit risk profile by internally assigned grade
Loans	$ 1,728,619	$ 1,721,350
Pass
Credit risk profile by internally assigned grade
Loans	1,665,413	1,644,646
Special mention
Credit risk profile by internally assigned grade
Loans	28,769	38,076
Substandard
Credit risk profile by internally assigned grade
Loans	12,616	15,684
Substandard non-performing
Credit risk profile by internally assigned grade
Loans	21,821	22,944
Commercial and industrial
Credit risk profile by internally assigned grade
Loans	511,247	510,739
Commercial and industrial | Pass
Credit risk profile by internally assigned grade
Loans	492,970	486,140
Commercial and industrial | Special mention
Credit risk profile by internally assigned grade
Loans	7,104	12,983
Commercial and industrial | Substandard
Credit risk profile by internally assigned grade
Loans	3,025	3,616
Commercial and industrial | Substandard non-performing
Credit risk profile by internally assigned grade
Loans	8,148	8,000
Construction and development excluding undeveloped land
Credit risk profile by internally assigned grade
Loans	88,108	99,719
Construction and development excluding undeveloped land | Pass
Credit risk profile by internally assigned grade
Loans	77,048	87,896
Construction and development excluding undeveloped land | Special mention
Credit risk profile by internally assigned grade
Loans	5,944	7,091
Construction and development excluding undeveloped land | Substandard
Credit risk profile by internally assigned grade
Loans	4,682	4,706
Construction and development excluding undeveloped land | Substandard non-performing
Credit risk profile by internally assigned grade
Loans	434	26
Undeveloped land
Credit risk profile by internally assigned grade
Loans	29,209	29,871
Undeveloped land | Pass
Credit risk profile by internally assigned grade
Loans	21,517	22,366
Undeveloped land | Special mention
Credit risk profile by internally assigned grade
Loans	540
Undeveloped land | Substandard
Credit risk profile by internally assigned grade
Loans	164	165
Undeveloped land | Substandard non-performing
Credit risk profile by internally assigned grade
Loans	6,988	7,340
Real estate mortgage
Credit risk profile by internally assigned grade
Loans	1,066,595	1,046,823
Real estate mortgage | Pass
Credit risk profile by internally assigned grade
Loans	1,040,582	1,014,216
Real estate mortgage | Special mention
Credit risk profile by internally assigned grade
Loans	15,099	17,916
Real estate mortgage | Substandard
Credit risk profile by internally assigned grade
Loans	4,745	7,197
Real estate mortgage | Substandard non-performing
Credit risk profile by internally assigned grade
Loans	6,169	7,494
Consumer
Credit risk profile by internally assigned grade
Loans	33,460	34,198
Consumer | Pass
Credit risk profile by internally assigned grade
Loans	33,296	34,028
Consumer | Special mention
Credit risk profile by internally assigned grade
Loans	82	86
Consumer | Substandard non-performing
Credit risk profile by internally assigned grade
Loans	$ 82	$ 84