Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Condensed Consolidated Balance Sheets [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 2,306	$ 2,408
Preferred stock, no par value
Preferred stock, shares authorized	250,000	250,000
Preferred stock, shares issued	0	0
Common stock, no par value
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	17,347,000	17,178,000