Condensed consolidating guarantor financial information - Income and Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Sep. 25, 2016	Jun. 26, 2016	Mar. 27, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Consolidated Guarantor Financial Information [Abstract]
Noncontrolling interest percent	100.00%								100.00%
Schedule Of Condensed Consolidating Statement Of Operations [Line Items]
Net revenues	$ 595,106	$ 534,703	$ 528,613	$ 487,881	$ 513,933	$ 455,648	$ 473,553	$ 424,893	$ 2,146,303	$ 1,868,027	$ 1,809,690
Cost of goods sold									974,501	871,827	865,287
Gross profit	330,731	295,227	290,284	255,560	273,052	241,602	256,399	225,147	1,171,802	996,200	944,403
Selling, general and administrative expenses									699,963	563,308	568,982
Research and development expenses									84,770	58,579	52,119
Restructuring and impairment charges									14,790	59,227	7,819
Gain on sale of assets									0	(4,367)	(408)
Income from continuing operations before interest, loss on extinguishment of debt and taxes	90,904	110,354	110,202	60,819	67,028	86,487	98,441	67,497	372,279	319,453	315,891
Interest, net									81,775	54,467	60,791
Loss on extinguishment of debt									5,593	19,261	10,454
Income from continuing operations before taxes									284,911	245,725	244,646
(Benefit) taxes on (loss) income from continuing operations									129,648	8,074	7,838
Equity in net income of consolidated subsidiaries									0	0	0
Income from continuing operations	(42,847)	79,398	78,363	40,349	60,876	66,200	59,395	51,180	155,263	237,651	236,808
Operating loss from discontinued operations									(4,534)	(922)	(1,730)
Benefit on loss from discontinued operations									(1,801)	(1,112)	(10,635)
(Loss) income on discontinued operations	189	(2,383)	(360)	(179)	187	122	193	(312)	(2,733)	190	8,905
Net income	(42,658)	77,015	78,003	40,170	61,063	66,322	59,588	50,868	152,530	237,841	245,713
Less: Income from continuing operations attributable to noncontrolling interest					0	0	285	179	0	464	850
Net income	$ (42,658)	$ 77,015	$ 78,003	$ 40,170	$ 61,063	$ 66,322	$ 59,303	$ 50,689	152,530	237,377	244,863
Other comprehensive income									173,626	(66,761)	(110,229)
Comprehensive income									326,156	170,616	134,634
Eliminations
Schedule Of Condensed Consolidating Statement Of Operations [Line Items]
Net revenues									(399,093)	(369,395)	(377,055)
Cost of goods sold									(398,179)	(368,725)	(374,995)
Gross profit									(914)	(670)	(2,060)
Selling, general and administrative expenses									196	(473)	(531)
Research and development expenses									0	0	0
Restructuring and impairment charges									0	0	0
Gain on sale of assets										0	0
Income from continuing operations before interest, loss on extinguishment of debt and taxes									(1,110)	(197)	(1,529)
Interest, net									0	0	0
Loss on extinguishment of debt									0	0	0
Income from continuing operations before taxes									(1,110)	(197)	(1,529)
(Benefit) taxes on (loss) income from continuing operations									(484)	(81)	38
Equity in net income of consolidated subsidiaries									(281,175)	(618,563)	(592,034)
Income from continuing operations									(281,801)	(618,679)	(593,601)
Operating loss from discontinued operations									0	0	0
Benefit on loss from discontinued operations									0	0	0
(Loss) income on discontinued operations									0	0	0
Net income									(281,801)	(618,679)	(593,601)
Less: Income from continuing operations attributable to noncontrolling interest										0	0
Net income										(618,679)	(593,601)
Other comprehensive income									(356,943)	156,798	231,043
Comprehensive income									(638,744)	(461,881)	(362,558)
Parent Company
Schedule Of Condensed Consolidating Statement Of Operations [Line Items]
Net revenues									0	0	0
Cost of goods sold									0	0	0
Gross profit									0	0	0
Selling, general and administrative expenses									47,412	43,602	42,435
Research and development expenses									1,009	547	0
Restructuring and impairment charges									0	173	0
Gain on sale of assets										(2,707)	0
Income from continuing operations before interest, loss on extinguishment of debt and taxes									(48,421)	(41,615)	(42,435)
Interest, net									195,649	153,830	132,711
Loss on extinguishment of debt									5,593	19,261	10,454
Income from continuing operations before taxes									(249,663)	(214,706)	(185,600)
(Benefit) taxes on (loss) income from continuing operations									(146,116)	(78,478)	(66,264)
Equity in net income of consolidated subsidiaries									258,810	374,048	355,138
Income from continuing operations									155,263	237,820	235,802
Operating loss from discontinued operations									(4,534)	(1,300)	(1,734)
Benefit on loss from discontinued operations									(1,801)	(857)	(10,795)
(Loss) income on discontinued operations									(2,733)	(443)	9,061
Net income									152,530	237,377	244,863
Less: Income from continuing operations attributable to noncontrolling interest										0	0
Net income										237,377	244,863
Other comprehensive income									173,626	(66,761)	(110,229)
Comprehensive income									326,156	170,616	134,634
Guarantor Subsidiaries
Schedule Of Condensed Consolidating Statement Of Operations [Line Items]
Net revenues									1,368,149	1,112,464	1,079,180
Cost of goods sold									778,153	652,442	646,427
Gross profit									589,996	460,022	432,753
Selling, general and administrative expenses									408,811	328,263	336,049
Research and development expenses									57,614	33,080	30,359
Restructuring and impairment charges									8,971	50,183	6,731
Gain on sale of assets										(155)	0
Income from continuing operations before interest, loss on extinguishment of debt and taxes									114,600	48,651	59,614
Interest, net									(117,431)	(103,465)	(76,873)
Loss on extinguishment of debt									0	0	0
Income from continuing operations before taxes									232,031	152,116	136,487
(Benefit) taxes on (loss) income from continuing operations									14,862	46,758	27,260
Equity in net income of consolidated subsidiaries									25,500	243,987	235,810
Income from continuing operations									242,669	349,345	345,037
Operating loss from discontinued operations									0	0	0
Benefit on loss from discontinued operations									0	0	0
(Loss) income on discontinued operations									0	0	0
Net income									242,669	349,345	345,037
Less: Income from continuing operations attributable to noncontrolling interest										0	0
Net income										349,345	345,037
Other comprehensive income									158,490	(76,098)	(110,604)
Comprehensive income									401,159	273,247	234,433
Non-Guarantor Subsidiaries
Schedule Of Condensed Consolidating Statement Of Operations [Line Items]
Net revenues									1,177,247	1,124,958	1,107,565
Cost of goods sold									594,527	588,110	593,855
Gross profit									582,720	536,848	513,710
Selling, general and administrative expenses									243,544	191,916	191,029
Research and development expenses									26,147	24,952	21,760
Restructuring and impairment charges									5,819	8,871	1,088
Gain on sale of assets										(1,505)	(408)
Income from continuing operations before interest, loss on extinguishment of debt and taxes									307,210	312,614	300,241
Interest, net									3,557	4,102	4,953
Loss on extinguishment of debt									0	0	0
Income from continuing operations before taxes									303,653	308,512	295,288
(Benefit) taxes on (loss) income from continuing operations									261,386	39,875	46,804
Equity in net income of consolidated subsidiaries									(3,135)	528	1,086
Income from continuing operations									39,132	269,165	249,570
Operating loss from discontinued operations									0	378	4
Benefit on loss from discontinued operations									0	(255)	160
(Loss) income on discontinued operations									0	633	(156)
Net income									39,132	269,798	249,414
Less: Income from continuing operations attributable to noncontrolling interest										464	850
Net income										269,334	248,564
Other comprehensive income									198,453	(80,700)	(120,439)
Comprehensive income									$ 237,585	$ 188,634	$ 128,125