Bank subsidiary (Details 10) (USD $) In Thousands, unless otherwise specified			12 Months Ended				12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011 Minimum grade	Dec. 31, 2011 Maximum grade	Dec. 31, 2011 Pass	Dec. 31, 2010 Pass	Dec. 31, 2011 Pass Minimum grade	Dec. 31, 2011 Pass Maximum grade	Dec. 31, 2011 Special mention	Dec. 31, 2010 Special mention	Dec. 31, 2011 Substandard	Dec. 31, 2010 Substandard	Dec. 31, 2011 Doubtful	Dec. 31, 2010 Doubtful	Dec. 31, 2010 Loss
Credit risk profile by internally assigned grade for loans
Categorization of loan grades considered pass grades			1	6			1	6
Commercial real estate	$ 331,931	$ 300,689			$ 308,843	$ 285,624			$ 8,594	$ 526	$ 11,058	$ 14,539	$ 3,436
Commercial construction	41,950	38,079			41,950	38,079
Commercial	$ 716,427	$ 551,683			$ 650,234	$ 462,078			$ 14,660	$ 44,759	$ 47,607	$ 44,259	$ 3,926	$ 556	$ 31