Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current assets:
Allowance for doubtful accounts	$ 115	$ 115
Stockholders' equity:
Preferred stock, par value (in dollars per share)	$ 25	$ 25
Preferred stock, authorized (in shares)	2,000,000	2,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0667	$ 0.0667
Common stock, authorized (in shares)	60,000,000	60,000,000
Common stock, issued (in shares)	30,225,763	29,454,171
Common stock, outstanding (in shares)	30,225,763	29,454,171