Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accounts and notes receivable, allowance	$ 2,497	$ 2,079
Accumulated depreciation	$ 398,630	$ 360,722
Common stock, shares outstanding	45,300,000	44,954,000
Treasury stock, shares		7,175,775
Common Class A
Common stock, par value		$ 0.0001
Common stock, shares authorized		125,000,000
Common stock, shares issued		52,129,395
Common stock, shares outstanding		44,953,620
Ordinary Shares
Common stock, par value	$ 0.01
Common stock, shares issued	45,300,164
Common stock, shares outstanding	45,300,164