Composition of Certain Financial Statement Items (Details Textual) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Jun. 30, 2009	Jun. 30, 2012	Dec. 31, 2011
Allowance for doubtful accounts (in thousands of dollars)					$ 0	$ 186
Payments to Acquire Notes Receivable				225
Provision for Loan, Lease, and Other Losses	40		146
Financing Receivable, Recorded Investment, Nonaccrual Status	39					39
Payments to Acquire Lease Receivables		$ 248
Acquired Lease Receivables Description	the Company acquired a lease receivable in the amount of $248, which is being reduced by monthly payments of $12 that began in April 2011.