Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Trade accounts receivable, allowance for doubtful accounts	$ 11,587	$ 9,248
Preferred stock, Shares authorized	5,000,000	5,000,000
Common stock, Shares authorized	400,000,000	400,000,000
Common stock, Shares issued	296,440,794	296,753,544
Common stock, Shares outstanding	296,440,794	296,753,544