Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Customer receivables, allowances	$ 8,067	$ 8,561
Common stock, par value	$ 0.10	$ 0.10
Common stock, shares authorized	140,000,000	140,000,000
Common stock, shares outstanding	86,164,917	86,164,917