Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Other comprehensive earnings (loss) [Abstract]
Tax benefit (expense) on cash flow hedging activities	$ 1,340	$ (11,190)	$ 8,259
Tax benefit (expense) on unrealized holding gains	(94)	364	(1,077)
Tax benefit (expense) on unrecognized pension and postretirement amounts	12,945	(928)	23,869
Reclassifications to earnings, tax effect: Tax (benefit) expense on cash flow hedging activities	4,098	5,435	(2,488)
Reclassifications to earnings, tax effect: Tax (benefit) expense on unrecognized pension and postretirement amounts	(3,038)	(1,861)	(1,327)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Total	15,251	(8,180)	27,236
Gain On Cash Flow Hedge Ineffectiveness Net Of Tax	1,428	1,111	58
Foreign Currency and Interest Rate Cash Flow Hedge Gain (Loss) To Be Reclassified During Next12 Months Net Of Tax	24,476
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive earnings (loss), Beginning of Year	(146,001)	(95,454)	(34,135)
Other comprehensive (loss) earnings	52	(3,289)	(67,676)
Reclassifications from AOCE to earnings	(48,621)	(47,258)	6,357
Total accumulated other comprehensive earnings (loss), End of Period	(194,570)	(146,001)	(95,454)
Pension and Postretirement Amounts [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive earnings (loss), Beginning of Year	(102,931)	(113,092)	(64,841)
Other comprehensive (loss) earnings	(20,829)	6,892	(51,206)
Reclassifications from AOCE to earnings	5,359	3,269	2,955
Total accumulated other comprehensive earnings (loss), End of Period	(118,401)	(102,931)	(113,092)
Gains (Losses) On Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive earnings (loss), Beginning of Year	79,317	43,689	(7,313)
Other comprehensive (loss) earnings	25,748	86,155	47,600
Reclassifications from AOCE to earnings	(53,980)	(50,527)	3,402
Total accumulated other comprehensive earnings (loss), End of Period	51,085	79,317	43,689
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive earnings (loss), Beginning of Year	(123,645)	(27,951)	38,019
Other comprehensive (loss) earnings	(5,033)	(95,694)	(65,970)
Reclassifications from AOCE to earnings	0	0	0
Total accumulated other comprehensive earnings (loss), End of Period	(128,678)	(123,645)	(27,951)
Unrealized Holding Gains on Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive earnings (loss), Beginning of Year	1,258	1,900	0
Other comprehensive (loss) earnings	166	(642)	1,900
Reclassifications from AOCE to earnings	0	0	0
Total accumulated other comprehensive earnings (loss), End of Period	1,424	$ 1,258	$ 1,900
Interest Rate Contract [Member] | Gains (Losses) On Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive earnings (loss), End of Period	(18,216)
Foreign Exchange Forward [Member] | Gains (Losses) On Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive earnings (loss), End of Period	$ (69,301)