Cash and cash equivalents (Details Textual) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011		Sep. 30, 2011	Dec. 31, 2010
Cash and Cash Equivalents, at Carrying Value	$ 4,864	$ 4,864	$ 3,704	[1]	$ 3,536	$ 8,434
Cash, FDIC Insured Amount	2,543
Cash, Uninsured Amount	$ 2,241

[1] Derived from audited financial information