Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Accounts and notes receivable, allowances	$ 44,341	$ 44,155
Accumulated Amortization	$ 31,260	$ 26,030
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares outstanding	59,980,023	59,812,796