Condensed Consolidated Balance Sheets [Parenthetical] (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Allowance for doubtful accounts, trade accounts	$ 517	$ 521
Imputed interest, advance to supplier amortization amount	235	292
Imputed interest, advance to supplier amortization amount, current	130	234
Unamortized discount, subordinated convertible debt	$ 1,651	$ 1,933
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	20,000,000	20,000,000
Common stock, issued (in shares)	11,749,651	11,749,651
Treasury stock (in shares)	3,165,249	3,158,597