Condensed consolidating guarantor financial information - Cash Flows (Details) - USD ($) $ in Thousands	9 Months Ended
	Oct. 01, 2017	Sep. 25, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities from continuing operations	$ 319,708	$ 301,598
Cash flows from investing activities of continuing operations:
Expenditures for property, plant and equipment	(53,977)	(35,912)
Proceeds from sale of assets	6,332	9,792
Payments for businesses and intangibles acquired, net of cash acquired	(1,010,711)	(14,040)
Net cash used in investing activities from continuing operations	(1,058,356)	(40,160)
Cash flows from financing activities of continuing operations:
Proceeds from new borrowings	1,963,500	671,700
Reduction in borrowings	(747,576)	(714,487)
Debt extinguishment, issuance and amendment fees	(19,114)	(8,958)
Net proceeds from share based compensation plans and the related tax impacts	4,739	7,647
Payments to noncontrolling interest shareholders	0	464
Payments for contingent consideration	(245)	(133)
Payments for acquisition of noncontrolling interest	0	(9,231)
Dividends paid	(45,905)	(43,980)
Intercompany transactions	0	0
Intercompany dividends paid	0	0
Net cash provided by (used in) financing activities from continuing operations	1,155,399	(97,906)
Cash flows from discontinued operations:
Net cash used in operating activities	(1,140)	(1,451)
Net cash used in discontinued operations	(1,140)	(1,451)
Effect of exchange rate changes on cash and cash equivalents	58,173	(988)
Net increase in cash and cash equivalents	473,784	161,093
Cash and cash equivalents at the beginning of the period	543,789	338,366
Cash and cash equivalents at the end of the period	1,017,573	499,459
Eliminations
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities from continuing operations	(61,918)	(2,275)
Cash flows from investing activities of continuing operations:
Expenditures for property, plant and equipment	0	0
Proceeds from sale of assets	(464,982)	(46,837)
Payments for businesses and intangibles acquired, net of cash acquired	0	46,837
Net cash used in investing activities from continuing operations	(464,982)	0
Cash flows from financing activities of continuing operations:
Proceeds from new borrowings	0	0
Reduction in borrowings	0	0
Debt extinguishment, issuance and amendment fees	0	0
Net proceeds from share based compensation plans and the related tax impacts	0	0
Payments to noncontrolling interest shareholders		0
Payments for contingent consideration	0	0
Payments for acquisition of noncontrolling interest		0
Dividends paid	0	0
Intercompany transactions	464,982	0
Intercompany dividends paid	61,918	2,275
Net cash provided by (used in) financing activities from continuing operations	526,900	2,275
Cash flows from discontinued operations:
Net cash used in operating activities	0	0
Net cash used in discontinued operations	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase in cash and cash equivalents	0	0
Cash and cash equivalents at the beginning of the period	0	0
Cash and cash equivalents at the end of the period	0	0
Parent Company
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities from continuing operations	(156,643)	(72,542)
Cash flows from investing activities of continuing operations:
Expenditures for property, plant and equipment	(233)	(191)
Proceeds from sale of assets	464,982	5,607
Payments for businesses and intangibles acquired, net of cash acquired	(975,524)	0
Net cash used in investing activities from continuing operations	(510,775)	5,416
Cash flows from financing activities of continuing operations:
Proceeds from new borrowings	1,963,500	665,000
Reduction in borrowings	(747,576)	(714,487)
Debt extinguishment, issuance and amendment fees	(19,114)	(8,958)
Net proceeds from share based compensation plans and the related tax impacts	4,739	7,647
Payments to noncontrolling interest shareholders		0
Payments for contingent consideration	0	0
Payments for acquisition of noncontrolling interest		0
Dividends paid	(45,905)	(43,980)
Intercompany transactions	(456,468)	175,203
Intercompany dividends paid	0	0
Net cash provided by (used in) financing activities from continuing operations	699,176	80,425
Cash flows from discontinued operations:
Net cash used in operating activities	(1,140)	(1,451)
Net cash used in discontinued operations	(1,140)	(1,451)
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase in cash and cash equivalents	30,618	11,848
Cash and cash equivalents at the beginning of the period	14,571	21,612
Cash and cash equivalents at the end of the period	45,189	33,460
Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities from continuing operations	300,961	123,249
Cash flows from investing activities of continuing operations:
Expenditures for property, plant and equipment	(27,527)	(15,713)
Proceeds from sale of assets	0	49,571
Payments for businesses and intangibles acquired, net of cash acquired	0	(10,305)
Net cash used in investing activities from continuing operations	(27,527)	23,553
Cash flows from financing activities of continuing operations:
Proceeds from new borrowings	0	0
Reduction in borrowings	0	0
Debt extinguishment, issuance and amendment fees	0	0
Net proceeds from share based compensation plans and the related tax impacts	0	0
Payments to noncontrolling interest shareholders		0
Payments for contingent consideration	(245)	(133)
Payments for acquisition of noncontrolling interest		0
Dividends paid	0	0
Intercompany transactions	474,192	(145,645)
Intercompany dividends paid	0	0
Net cash provided by (used in) financing activities from continuing operations	473,947	(145,778)
Cash flows from discontinued operations:
Net cash used in operating activities	0	0
Net cash used in discontinued operations	0	0
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase in cash and cash equivalents	747,381	1,024
Cash and cash equivalents at the beginning of the period	1,031	0
Cash and cash equivalents at the end of the period	748,412	1,024
Non-Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities from continuing operations	237,308	253,166
Cash flows from investing activities of continuing operations:
Expenditures for property, plant and equipment	(26,217)	(20,008)
Proceeds from sale of assets	6,332	1,451
Payments for businesses and intangibles acquired, net of cash acquired	(35,187)	(50,572)
Net cash used in investing activities from continuing operations	(55,072)	(69,129)
Cash flows from financing activities of continuing operations:
Proceeds from new borrowings	0	6,700
Reduction in borrowings	0	0
Debt extinguishment, issuance and amendment fees	0	0
Net proceeds from share based compensation plans and the related tax impacts	0	0
Payments to noncontrolling interest shareholders		464
Payments for contingent consideration	0	0
Payments for acquisition of noncontrolling interest		(9,231)
Dividends paid	0	0
Intercompany transactions	(482,706)	(29,558)
Intercompany dividends paid	(61,918)	(2,275)
Net cash provided by (used in) financing activities from continuing operations	(544,624)	(34,828)
Cash flows from discontinued operations:
Net cash used in operating activities	0	0
Net cash used in discontinued operations	0	0
Effect of exchange rate changes on cash and cash equivalents	58,173	(988)
Net increase in cash and cash equivalents	(304,215)	148,221
Cash and cash equivalents at the beginning of the period	528,187	316,754
Cash and cash equivalents at the end of the period	$ 223,972	$ 464,975