Notes Payable and Revolving Credit Agreement (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Summary of notes payable
Long-term debt, total	$ 16,884	$ 24,217
Less current portion	(609)	(433)
Long term portion	16,275	23,784
Revolving credit agreement average effective interest rate of 3.7% inclusive of unused fee [Member]
Summary of notes payable
Long-term debt, total	16,100	23,500
Promissory note payable in annual installments of $100 plus accrued interest through December 31, 2012, interest accrues at 3.25% per annum [Member]
Summary of notes payable
Long-term debt, total	100	100
Promissory note payable in annual installments of $50 plus accrued interest through December 21, 2012, interest accrues at 4.00% per annum [Member]
Summary of notes payable
Long-term debt, total	50	50
Promissory note payable in annual installments of $184 plus accrued interest through June 30, 2013, interest accrues at 3.25% per annum [Member]
Summary of notes payable
Long-term debt, total	184	367
Promissory note payable in annual installments of $100 plus accrued interest through July 25, 2013, interest accrues at 3.25% per annum [Member]
Summary of notes payable
Long-term debt, total	100	200
Promissory note payable in annual installments of $50 plus accrued interest through January 3, 2014, interest accrues at 3.25% per annum [Member]
Summary of notes payable
Long-term debt, total	100
Promissory notes payable in aggregate annual installments of $125 plus accrued interest through May 22, 2014, interest accrues at 3.25% per annum [Member]
Summary of notes payable
Long-term debt, total	$ 250