Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Trade receivables, allowance for doubtful accounts	$ 2,722	$ 2,921
Common stock, par value	$ 0.0005	$ 0.0005
Common stock, shares authorized	350,000,000	350,000,000
Common stock, shares issued	170,417,372	175,323,885
Common stock, shares outstanding	170,417,372	175,323,885