Derivative Instruments And Hedging Activities Schedule of Realized Gain (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Price Risk Hedge Ineffectiveness	$ 5,442	$ 8,911	$ 32,817	$ 5,916
Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Price Risk Hedge Ineffectiveness	6,983	828	14,035	1,302
Operating Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Price Risk Hedge Ineffectiveness	(1,541)	8,083	(5,763)	4,614
Other Nonoperating Income (Expense) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Price Risk Hedge Ineffectiveness	$ 0	$ 0	$ 24,545	$ 0