Derivative Instruments And Hedging Activities Schedule of Realized Gain (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Price Risk Hedge Ineffectiveness	$ (11,261)	$ (4,729)	$ 21,556	$ 1,187
Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Price Risk Hedge Ineffectiveness	(10,632)	(2,438)	3,403	(1,135)
Operating Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Price Risk Hedge Ineffectiveness	(629)	(2,291)	(6,392)	2,322
Other Nonoperating Income (Expense) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Price Risk Hedge Ineffectiveness	$ 0	$ 0	$ 24,545	$ 0