Consolidated Balance Sheets (unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Accounts and notes receivable, allowances	$ 13,020	$ 13,538
Property and equipment, accumulated depreciation	$ 208,749	$ 201,399
Common stock, par value (in USD per share)	$ 2	$ 2
Common stock, authorized (shares)	200,000,000	200,000,000
Common stock, issued (shares)	61,202,000	61,031,000
Common stock, outstanding (shares)	61,202,000	61,031,000