Derivative Instruments and Hedging Activities Location of Gain Loss in Income Statement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Economic Hedges, Gain (Loss)	$ 5,521	$ (6,133)	$ 36,079
Cost of products sold
Derivative Instruments, Gain (Loss) [Line Items]
Economic Hedges, Gain (Loss)	(12,327)	(6,889)	48,082
Operating expenses
Derivative Instruments, Gain (Loss) [Line Items]
Economic Hedges, Gain (Loss)	(6,697)	7,276	(12,003)
Other Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Economic Hedges, Gain (Loss)	$ 24,545	$ (6,520)	$ 0