Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Consolidated Balance Sheets [Abstract]
Accounts receivable, allowances	$ 1,994	$ 2,066
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	200,000	200,000
Common stock, shares issued	28,859	28,793
Common stock, shares outstanding	25,090	25,152
Treasury stock, shares	3,769	3,641