Fair Value of Financial Instruments, Assests and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2018	Dec. 31, 2017	Apr. 02, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, assets	$ 2,941	$ 3,126	$ 3,687
Derivatives, assets	2,960	12,226	56,017
Total assets, fair value hierarchy	5,901	15,352	59,704
Derivatives, liabilities	39,428	23,051	20,595
Option Agreement	23,665	23,980	28,710
Total Liabilities	$ 63,093	47,031	49,305
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	45 days
Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	30 days
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	90 days
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, assets	$ 2,941	3,126	3,687
Derivatives, assets	0	0	0
Total assets, fair value hierarchy	2,941	3,126	3,687
Derivatives, liabilities	0	0	0
Option Agreement	0	0	0
Total Liabilities	0	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, assets	0	0	0
Derivatives, assets	2,960	12,226	56,017
Total assets, fair value hierarchy	2,960	12,226	56,017
Derivatives, liabilities	39,428	23,051	20,595
Option Agreement	0	0	0
Total Liabilities	39,428	23,051	20,595
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, assets	0	0	0
Derivatives, assets	0	0	0
Total assets, fair value hierarchy	0	0	0
Derivatives, liabilities	0	0	0
Option Agreement	23,665	23,980	28,710
Total Liabilities	$ 23,665	$ 23,980	$ 28,710