Loans (Details 7) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Credit risk profile by internally assigned grade
Loans	$ 1,709,258	$ 1,584,594
Pass
Credit risk profile by internally assigned grade
Loans	1,627,513	1,479,820
Special mention
Credit risk profile by internally assigned grade
Loans	38,076	44,698
Substandard
Credit risk profile by internally assigned grade
Loans	13,185	31,383
Substandard non-performing
Credit risk profile by internally assigned grade
Loans	30,484	28,693
Commercial and industrial
Credit risk profile by internally assigned grade
Loans	500,478	426,930
Commercial and industrial | Pass
Credit risk profile by internally assigned grade
Loans	477,981	404,045
Commercial and industrial | Special mention
Credit risk profile by internally assigned grade
Loans	12,983	11,097
Commercial and industrial | Substandard
Credit risk profile by internally assigned grade
Loans	365	4,482
Commercial and industrial | Substandard non-performing
Credit risk profile by internally assigned grade
Loans	9,149	7,306
Construction and development
Credit risk profile by internally assigned grade
Loans	135,786	131,253
Construction and development | Pass
Credit risk profile by internally assigned grade
Loans	109,223	113,559
Construction and development | Special mention
Credit risk profile by internally assigned grade
Loans	7,091	6,831
Construction and development | Substandard
Credit risk profile by internally assigned grade
Loans	9,602
Construction and development | Substandard non-performing
Credit risk profile by internally assigned grade
Loans	9,870	10,863
Real estate mortgage
Credit risk profile by internally assigned grade
Loans	1,038,864	989,631
Real estate mortgage | Pass
Credit risk profile by internally assigned grade
Loans	1,006,353	925,674
Real estate mortgage | Special mention
Credit risk profile by internally assigned grade
Loans	17,916	26,770
Real estate mortgage | Substandard
Credit risk profile by internally assigned grade
Loans	3,218	26,901
Real estate mortgage | Substandard non-performing
Credit risk profile by internally assigned grade
Loans	11,377	10,286
Consumer
Credit risk profile by internally assigned grade
Loans	34,130	36,780
Consumer | Pass
Credit risk profile by internally assigned grade
Loans	33,956	36,542
Consumer | Special mention
Credit risk profile by internally assigned grade
Loans	86
Consumer | Substandard non-performing
Credit risk profile by internally assigned grade
Loans	$ 88	$ 238