Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Accounts and notes receivable, allowances	$ 13,220	$ 13,306
Property and equipment, accumulated depreciation	$ 173,278	$ 163,377
Common stock, par value	$ 2	$ 2
Common stock, authorized	200,000,000	200,000,000
Common stock, issued	63,018,000	63,070,000
Common stock, outstanding	63,018,000	63,070,000