Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Aug. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2012	Nov. 30, 2011
Debt Instrument [Line Items]
Total debt	$ 833,879		$ 751,555
Less: Current maturities of long-term debt	0		(129,706)
Long-term debt	$ 833,879		$ 621,849
Variable interest rate	6.21%		6.21%	6.21%
Senior Notes due 2022 at a fixed interest rate of 3.75%
Debt Instrument [Line Items]
Total debt	$ 325,000		$ 325,000
Fixed interest rate	3.75%		3.75%		3.75%
Senior Exchangeable Notes due 2015 at a fixed interest rate of 4.50%
Debt Instrument [Line Items]
Total debt	$ 0		$ 129,706
Fixed interest rate	4.50%	4.50%	4.50%	4.50%
Mortgage notes due 2017 at fixed interest rates of 4.35%
Debt Instrument [Line Items]
Total debt	$ 42,638		$ 53,801
Fixed interest rate	4.35%		4.35%			4.35%
Solid waste bonds due 2020 at a variable interest rate of 1.3% at December 31, 2015
Debt Instrument [Line Items]
Total debt	$ 15,000		$ 15,000
Fixed interest rate	1.30%		1.30%
Revolving Credit Facility borrowings at a variable interest rate of 1.34% at December 31, 2014
Debt Instrument [Line Items]
Total debt	$ 0		$ 16,000
Variable interest rate			1.34%
Revolving Credit Facility borrowings due 2020 at a variable interest rate of 1.6% at December 31, 2015
Debt Instrument [Line Items]
Total debt	$ 97,000		$ 0
Variable interest rate	1.60%
Term Credit Agreement borrowings due 2024 at a variable interest rate of 1.9% at December 31, 2015
Debt Instrument [Line Items]
Total debt	$ 170,000		0
Variable interest rate	1.90%
New Zealand JV Revolving Credit Facility due 2016 at a variable interest rate of 3.54% at December 31, 2015
Debt Instrument [Line Items]
Total debt	$ 160,999		184,099
Variable interest rate	3.54%
New Zealand JV Noncontrolling interest shareholder loan at 0% interest rate
Debt Instrument [Line Items]
Total debt	$ 23,242		$ 27,949
Fixed interest rate	0.00%		0.00%