Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Condensed Consolidated Balance Sheets [Abstract]
Allowances for accounts receivable	$ 1,220	$ 1,294
Preferred stock, par value
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par value
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	60,624,655	61,038,507
Common stock, shares outstanding	60,624,655	61,038,507