Condensed consolidating guarantor financial information Condensed consolidating statements of income and comprehensive income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Condensed Income Statements, Captions [Line Items]
Net revenues	$ 443,714	$ 457,173	$ 1,325,189	$ 1,363,824
Cost of goods sold	215,501	221,007	641,102	662,411
Gross profit	228,213	236,166	684,087	701,413
Selling, general and administrative expenses	138,840	138,252	420,765	425,392
Research and development expenses	12,571	14,871	38,898	43,803
Restructuring charges	660	1,108	5,688	16,511
Gain on sale of assets	(408)	0	(408)	0
Income from continuing operations before interest, extinguishment of debt and taxes	76,550	81,935	219,144	215,707
Interest, net	14,176	17,023	47,232	48,156
Interest income	130	161	453	494
Loss on extinguishment of debt	0	0	10,454	0
Income from continuing operations before taxes	62,374	64,912	161,458	167,551
(Benefit) taxes on income from continuing operations	803	9,684	15,415	28,224
Equity in net income of consolidated subsidiaries	0	0	0	0
Income from continuing operations	61,571	55,228	146,043	139,327
Operating loss from discontinued operations	(788)	(247)	(1,432)	(1,866)
(Benefit) taxes on loss from discontinued operations	(69)	24	180	(345)
Loss from discontinued operations	(719)	(271)	(1,612)	(1,521)
Net income	60,852	54,957	144,431	137,806
Less: Income from continuing operations attributable to noncontrolling interest	28	126	692	765
Net income attributable to common shareholders	60,824	54,831	143,739	137,041
Other comprehensive income attributable to common shareholders	(28,789)	(45,201)	(89,004)	(38,594)
Comprehensive income attributable to common shareholders	32,035	9,630	54,735	98,447
Consolidation, Eliminations
Condensed Income Statements, Captions [Line Items]
Net revenues	(95,990)	(76,256)	(283,538)	(288,398)
Cost of goods sold	(97,273)	(76,817)	(278,689)	(278,691)
Gross profit	1,283	561	(4,849)	(9,707)
Selling, general and administrative expenses	106	(80)	23	231
Research and development expenses	0	0	0	0
Restructuring charges	0	0	0	0
Gain on sale of assets	0		0
Income from continuing operations before interest, extinguishment of debt and taxes	1,177	641	(4,872)	(9,938)
Interest, net	0		0
Loss on extinguishment of debt			0
Income from continuing operations before taxes	1,177	641	(4,872)	(9,938)
(Benefit) taxes on income from continuing operations	270	1,956	(1,000)	(2,303)
Equity in net income of consolidated subsidiaries	(138,824)	(145,578)	(399,481)	(389,054)
Income from continuing operations	(137,917)	(146,893)	(403,353)	(396,689)
Operating loss from discontinued operations	0	0	0	0
(Benefit) taxes on loss from discontinued operations	0	0	0	0
Loss from discontinued operations	0	0	0	0
Net income	(137,917)	(146,893)	(403,353)	(396,689)
Less: Income from continuing operations attributable to noncontrolling interest	0	0	0	0
Net income attributable to common shareholders	(137,917)	(146,893)	(403,353)	(396,689)
Other comprehensive income attributable to common shareholders	58,928	115,106	196,062	104,757
Comprehensive income attributable to common shareholders	(78,989)	(31,787)	(207,291)	(291,932)
Parent Company
Condensed Income Statements, Captions [Line Items]
Net revenues	0	0	0	0
Cost of goods sold	0	0	0	0
Gross profit	0	0	0	0
Selling, general and administrative expenses	9,891	8,978	30,006	30,781
Research and development expenses	0	0	0	0
Restructuring charges	0	0	0	0
Gain on sale of assets	0		0
Income from continuing operations before interest, extinguishment of debt and taxes	(9,891)	(8,978)	(30,006)	(30,781)
Interest, net	32,439	37,913	100,157	106,794
Loss on extinguishment of debt			10,454
Income from continuing operations before taxes	(42,330)	(46,891)	(140,617)	(137,575)
(Benefit) taxes on income from continuing operations	(15,102)	(16,761)	(48,336)	(47,891)
Equity in net income of consolidated subsidiaries	88,728	85,187	237,512	228,113
Income from continuing operations	61,500	55,057	145,231	138,429
Operating loss from discontinued operations	(784)	(247)	(1,432)	(1,866)
(Benefit) taxes on loss from discontinued operations	(108)	(21)	60	(478)
Loss from discontinued operations	(676)	(226)	(1,492)	(1,388)
Net income	60,824	54,831	143,739	137,041
Less: Income from continuing operations attributable to noncontrolling interest	0	0	0	0
Net income attributable to common shareholders	60,824	54,831	143,739	137,041
Other comprehensive income attributable to common shareholders	(28,789)	(45,201)	(89,004)	(38,594)
Comprehensive income attributable to common shareholders	32,035	9,630	54,735	98,447
Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Net revenues	269,620	261,346	803,484	814,051
Cost of goods sold	159,567	161,298	476,611	489,694
Gross profit	110,053	100,048	326,873	324,357
Selling, general and administrative expenses	82,372	77,352	249,484	235,322
Research and development expenses	6,006	12,871	22,027	37,766
Restructuring charges	602	148	4,932	8,639
Gain on sale of assets	0		0
Income from continuing operations before interest, extinguishment of debt and taxes	21,073	9,677	50,430	42,630
Interest, net	(19,457)	(22,346)	(56,591)	(62,993)
Loss on extinguishment of debt			0
Income from continuing operations before taxes	40,530	32,023	107,021	105,623
(Benefit) taxes on income from continuing operations	7,582	13,984	33,491	44,737
Equity in net income of consolidated subsidiaries	49,885	60,295	161,539	160,653
Income from continuing operations	82,833	78,334	235,069	221,539
Operating loss from discontinued operations	0	0	0	0
(Benefit) taxes on loss from discontinued operations	0	0	0	0
Loss from discontinued operations	0	0	0	0
Net income	82,833	78,334	235,069	221,539
Less: Income from continuing operations attributable to noncontrolling interest	0	0	0	0
Net income attributable to common shareholders	82,833	78,334	235,069	221,539
Other comprehensive income attributable to common shareholders	(32,855)	(58,947)	(94,601)	(54,326)
Comprehensive income attributable to common shareholders	49,978	19,387	140,468	167,213
Non-Guarantor Subsidiaries
Condensed Income Statements, Captions [Line Items]
Net revenues	270,084	272,083	805,243	838,171
Cost of goods sold	153,207	136,526	443,180	451,408
Gross profit	116,877	135,557	362,063	386,763
Selling, general and administrative expenses	46,471	52,002	141,252	159,058
Research and development expenses	6,565	2,000	16,871	6,037
Restructuring charges	58	960	756	7,872
Gain on sale of assets	(408)		(408)
Income from continuing operations before interest, extinguishment of debt and taxes	64,191	80,595	203,592	213,796
Interest, net	1,194	1,456	3,666	4,355
Loss on extinguishment of debt			0
Income from continuing operations before taxes	62,997	79,139	199,926	209,441
(Benefit) taxes on income from continuing operations	8,053	10,505	31,260	33,681
Equity in net income of consolidated subsidiaries	211	96	430	288
Income from continuing operations	55,155	68,730	169,096	176,048
Operating loss from discontinued operations	(4)	0	0	0
(Benefit) taxes on loss from discontinued operations	39	45	120	133
Loss from discontinued operations	(43)	(45)	(120)	(133)
Net income	55,112	68,685	168,976	175,915
Less: Income from continuing operations attributable to noncontrolling interest	28	126	692	765
Net income attributable to common shareholders	55,084	68,559	168,284	175,150
Other comprehensive income attributable to common shareholders	(26,073)	(56,159)	(101,461)	(50,431)
Comprehensive income attributable to common shareholders	$ 29,011	$ 12,400	$ 66,823	$ 124,719