Derivative Financial Instruments, Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type (Details) - Foreign Exchange Forward [Member] - USD ($) $ in Thousands	Apr. 01, 2018	Dec. 31, 2017	Apr. 02, 2017
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Net unrealized gain	$ (736)	$ (2,891)	$ (27)
Not Designated as Hedging Instrument [Member] | Accrued liabilities [Member]
Derivatives, Fair Value [Line Items]
Unrealized gains	383	1,793	289
Unrealized losses	(1,119)	(4,684)	(316)
Net unrealized gain	(736)	(2,891)	(27)
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Net unrealized gain	(35,732)	(7,934)	35,449
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Prepaid expenses and other current assets [Member]
Derivatives, Fair Value [Line Items]
Unrealized gains	458	13,666	23,241
Unrealized losses	(405)	(10,319)	(3,204)
Net unrealized gain	53	3,347	20,037
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Unrealized gains	5,996	11,255	39,032
Unrealized losses	(3,089)	(2,376)	(3,052)
Net unrealized gain	2,907	8,879	35,980
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Accrued liabilities [Member]
Derivatives, Fair Value [Line Items]
Unrealized gains	8,218	4,215	9,041
Unrealized losses	(30,826)	(15,484)	(28,591)
Net unrealized gain	(22,608)	(11,269)	(19,550)
Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Unrealized gains	2,846	4,546	149
Unrealized losses	(18,930)	(13,437)	(1,167)
Net unrealized gain	$ (16,084)	$ (8,891)	$ (1,018)