CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Trade receivables, allowance for doubtful accounts	$ 652	$ 450
Stockholders' equity:
Common Stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common Stock, shares authorized (in shares)	100,000,000	100,000,000
Common Stock, shares issued (in shares)	31,704,230	31,441,138
Treasury stock, at cost (in shares)	1,795,082	1,866,258