Long-term Debt Narrative (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) payments	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2017 CLP	May 01, 2012
Debt Instrument [Line Items]
Amortization of financing costs and discounts	$ 900,000	$ 1,100,000	$ 1,100,000
Notes Receivable	22,200,000	22,200,000
Impact of foreign currency exchange rates	(2,100,000)	2,000,000	(2,800,000)
Impact of UF change	400,000	3,800,000	800,000
Line of Credit Facility, Remaining Borrowing Capacity	200,000,000
Line of Credit Capacity, Sublimit for Letters of Credit	$ 60,000,000
Capitalization Ratio, Maximum	40.00%			40.00%
Required debt to equity ratio maximum	1
Required EBITDA to financial costs minimum	3
Loss on early debt extinguishment	$ 0	$ (17,300,000)	0
Debt, weighted average interest rate	5.10%	5.10%		5.10%
Interest paid, net	$ 17,500,000	$ 27,200,000	$ 36,900,000
Senior notes payable 2018 [Member]
Debt Instrument [Line Items]
Fair value of debt	22,400,000	23,400,000
Amount of loan issuance	348,600,000
Notes Payable	22,000,000
Notes Receivable	$ 22,200,000
Amount of indebtedness liable for in event of default of notes receivable collateral	10.00%			10.00%
Debt, interest rate, stated percentage	7.30%			7.30%
Chilean term credit facility, maturing 2019 [Member]
Debt Instrument [Line Items]
Amount of loan issuance	$ 39,000,000			CLP 943,543.7391
Repayments of Debt	6,800,000
Impact of foreign currency exchange rates	600,000.0
Impact of UF change	$ 100,000
Debt, interest rate, stated percentage	3.90%			3.90%
Ratio of indebtedness to net capital	2.5			2.5
Number of future semi-annual payments | payments	16
Brazilian export financing facility, maturing 2017 [Member]
Debt Instrument [Line Items]
Debt, interest rate, stated percentage	6.65%			6.65%
Number of future semi-annual payments | payments	10,000,000
Senior unsecured notes, maturing 2024 [Member]
Debt Instrument [Line Items]
Fair value of debt	$ 363,900,000	$ 344,000,000
Amount of loan issuance	$ 350,000,000
Debt, interest rate, stated percentage	4.90%			4.90%	4.875%
Base Rate
Debt Instrument [Line Items]
Line of credit facility, interest rate description	.005
Base Rate | Maximum
Debt Instrument [Line Items]
Line of credit facility, interest rate description	.0175
Base Rate | Minimum
Debt Instrument [Line Items]
Line of credit facility, interest rate description	.00625
London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Line of credit facility, interest rate description	.01
London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Line of credit facility, interest rate description	.0275
London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Line of credit facility, interest rate description	0.01625
Other Commitments [Domain] | Maximum
Debt Instrument [Line Items]
Line of credit facility, interest rate description	.005
Other Commitments [Domain] | Minimum
Debt Instrument [Line Items]
Line of credit facility, interest rate description	.0020