Income Taxes, Deferred Tax Asset Valuation Adjustments (Details) - Deferred Tax Asset Valuation Allowance [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Valuation Allowance [Roll Forward]
Beginning balance, adjustments to inventory carrying value		$ 49,271	[1]	$ 35,999	[1]	$ 10,803
Additions charged to cost and expenses		692		12,948		28,687
Decreases		(40,442)	[2]	(2,943)	[3]	(3,546)	[3]
Adjustments	[4]	(384)		3,267		55
Ending balance, adjustments to inventory carrying value		$ 9,137		$ 49,271	[1]	$ 35,999	[1]

[1] The increase was due primarily to the deferred tax assets created by the unrealized loss in Venezuela for which the Company set up a full valuation allowance.

[2] Decrease in valuation allowance due to lapse in statute of limitation of the net operating losses carryforward and due to the write off of Venezuelan deferred tax assets, which had no impact to the income statement.

[3] Decreases in valuation allowance due to lapse in statute of limitation of the net operating losses carryforward which had no impact to the income statement.

[4] Represents the net currency effects of translating valuation allowances at current rates of exchange.