Guarantor Financial Information (Condensed Consolidated Balance Sheet) (Details) - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 30, 2018	Dec. 29, 2018	Mar. 31, 2018	Dec. 30, 2017
ASSETS
Cash and cash equivalents	$ 95,716		$ 107,262
Restricted cash	107		107
Accounts receivable, net	371,339		385,737
Inventories	339,882		341,028
Income taxes refundable	4,102		6,462
Prepaid expenses	39,070		35,247
Other current assets	20,959		22,099
Total current assets	871,175		897,942
Investment in subsidiaries	0		0
Property, plant and equipment, net	1,691,558		1,687,858
Intangible assets, net	579,313		595,862
Goodwill	1,222,382		1,229,159
Investment in unconsolidated subsidiaries	433,381		410,177
Operating right-of-use assets, net	129,721	$ 135,700	0
Other assets	53,487		53,375
Deferred income taxes	14,037		14,981
Total assets	4,995,054		4,889,354
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current portion of long-term debt	23,693		7,492
Accounts payable	192,511		219,479
Income taxes payable	8,861		4,043
Operating lease liability, current	39,776		0
Accrued expenses	281,331		309,484
Total current liabilities	546,172		540,498
Long-term debt, net of current portion	1,663,763		1,666,940
Operating lease liability, non-current	89,100		0
Other non-current liabilities	113,984		115,032
Deferred income taxes	225,336		231,063
Total liabilities	2,638,355		2,553,533
Total stockholders’ equity	2,356,699		2,335,821	$ 2,439,239	$ 2,327,697
Total liabilities and stockholders' equity	4,995,054		4,889,354
Parent [Member]
ASSETS
Cash and cash equivalents	987		995
Restricted cash	103		103
Accounts receivable, net	43,885		56,113
Inventories	19,211		23,752
Income taxes refundable	1,426		2,851
Prepaid expenses	12,155		12,890
Other current assets	3,355		2,680
Total current assets	81,122		99,384
Investment in subsidiaries	4,934,820		4,880,193
Property, plant and equipment, net	392,718		375,824
Intangible assets, net	48,619		50,132
Goodwill	49,902		49,506
Investment in unconsolidated subsidiaries	13,078		13,969
Operating right-of-use assets, net	75,150
Other assets	38,490		39,395
Deferred income taxes	0		0
Total assets	5,633,899		5,508,403
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current portion of long-term debt	11,908		3,558
Accounts payable	807,675		783,406
Income taxes payable	300		(10)
Operating lease liability, current	21,546
Accrued expenses	85,734		107,572
Total current liabilities	927,163		894,526
Long-term debt, net of current portion	1,032,803		1,019,130
Operating lease liability, non-current	53,587
Other non-current liabilities	78,220		78,589
Deferred income taxes	95,191		95,710
Total liabilities	2,186,964		2,087,955
Total stockholders’ equity	3,446,935		3,420,448
Total liabilities and stockholders' equity	5,633,899		5,508,403
Guarantors [Member]
ASSETS
Cash and cash equivalents	33		32
Restricted cash	0		0
Accounts receivable, net	640,838		619,628
Inventories	85,113		83,261
Income taxes refundable	0		0
Prepaid expenses	2,508		2,936
Other current assets	(1,980)		(1,418)
Total current assets	726,512		704,439
Investment in subsidiaries	1,366,126		1,366,126
Property, plant and equipment, net	503,739		503,130
Intangible assets, net	193,338		200,936
Goodwill	490,748		490,748
Investment in unconsolidated subsidiaries	0		0
Operating right-of-use assets, net	34,974
Other assets	140		138
Deferred income taxes	0		0
Total assets	3,315,577		3,265,517
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current portion of long-term debt	5		5
Accounts payable	27,833		24,388
Income taxes payable	0		0
Operating lease liability, current	10,673
Accrued expenses	27,109		33,387
Total current liabilities	65,620		57,780
Long-term debt, net of current portion	16		18
Operating lease liability, non-current	23,701
Other non-current liabilities	0		0
Deferred income taxes	0		0
Total liabilities	89,337		57,798
Total stockholders’ equity	3,226,240		3,207,719
Total liabilities and stockholders' equity	3,315,577		3,265,517
Non-guarantors [Member]
ASSETS
Cash and cash equivalents	94,696		106,235
Restricted cash	4		4
Accounts receivable, net	468,164		461,005
Inventories	235,558		234,015
Income taxes refundable	2,676		3,611
Prepaid expenses	24,407		19,421
Other current assets	19,584		20,837
Total current assets	845,089		845,128
Investment in subsidiaries	844,044		844,044
Property, plant and equipment, net	795,101		808,904
Intangible assets, net	337,356		344,794
Goodwill	681,732		688,905
Investment in unconsolidated subsidiaries	420,303		396,208
Operating right-of-use assets, net	19,597
Other assets	14,857		13,842
Deferred income taxes	14,037		14,981
Total assets	3,972,116		3,956,806
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current portion of long-term debt	11,780		3,929
Accounts payable	138,539		162,678
Income taxes payable	8,561		4,053
Operating lease liability, current	7,557
Accrued expenses	168,500		168,541
Total current liabilities	334,937		339,201
Long-term debt, net of current portion	630,944		647,792
Operating lease liability, non-current	11,812
Other non-current liabilities	35,764		36,443
Deferred income taxes	130,145		135,353
Total liabilities	1,143,602		1,158,789
Total stockholders’ equity	2,828,514		2,798,017
Total liabilities and stockholders' equity	3,972,116		3,956,806
Eliminations [Member]
ASSETS
Operating right-of-use assets, net	0
LIABILITIES AND STOCKHOLDERS’ EQUITY
Operating lease liability, current	0
Operating lease liability, non-current	0
Eliminations [Member]
ASSETS
Cash and cash equivalents	0		0
Restricted cash	0		0
Accounts receivable, net	(781,548)		(751,009)
Inventories	0		0
Income taxes refundable	0		0
Prepaid expenses	0		0
Other current assets	0		0
Total current assets	(781,548)		(751,009)
Investment in subsidiaries	(7,144,990)		(7,090,363)
Property, plant and equipment, net	0		0
Intangible assets, net	0		0
Goodwill	0		0
Investment in unconsolidated subsidiaries	0		0
Other assets	0		0
Deferred income taxes	0		0
Total assets	(7,926,538)		(7,841,372)
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current portion of long-term debt	0		0
Accounts payable	(781,536)		(750,993)
Income taxes payable	0		0
Accrued expenses	(12)		(16)
Total current liabilities	(781,548)		(751,009)
Long-term debt, net of current portion	0		0
Other non-current liabilities	0		0
Deferred income taxes	0		0
Total liabilities	(781,548)		(751,009)
Total stockholders’ equity	(7,144,990)		(7,090,363)
Total liabilities and stockholders' equity	$ (7,926,538)		$ (7,841,372)