Operating Segments and Geographic Information - Operating Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 03, 2016	Jun. 28, 2015	Jul. 03, 2016	Jun. 28, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Segment revenues	$ 601,631	$ 585,755	$ 1,143,128	$ 1,132,712
Depreciation expense	12,000	11,700	23,700	23,200
Amortization expense	26,263	25,917	51,795	52,421
Severance, restructuring, and acquisition integration costs	5,869	4,907	14,277	19,390
Segment assets	3,254,890		3,254,890		$ 3,290,602
Broadcast Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs	1,319	3,283	5,697	14,810
Enterprise Connectivity Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs	1,207	83	1,707	651
Industrial Connectivity Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs	2,371	1,163	3,236	2,936
Network Security Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs	29	378	29	1,045
Reportable Segment [Member]
Segment Reporting Information [Line Items]
Segment revenues	603,381	598,513	1,147,181	1,167,964
Affiliate revenues	1,719	2,126	4,052	4,450
Segment EBITDA	108,335	100,300	198,401	188,597
Depreciation expense	11,987	11,692	23,650	23,233
Amortization expense	26,263	25,917	51,795	52,421
Severance, restructuring, and acquisition integration costs	5,869	4,907	14,277	19,390
Purchase accounting effects of acquisitions			195	9,422
Deferred gross profit adjustments	1,750	13,440	4,053	35,098
Segment assets	945,100	1,005,496	945,100	1,005,496
Reportable Segment [Member] | Broadcast Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues	193,521	174,923	364,793	351,423
Affiliate revenues	173		597
Segment EBITDA	29,505	22,878	52,772	46,005
Depreciation expense	4,061	4,140	8,023	8,113
Amortization expense	13,420	12,595	26,351	25,021
Severance, restructuring, and acquisition integration costs	1,319	3,283	5,697	14,810
Purchase accounting effects of acquisitions			195
Deferred gross profit adjustments	494	(924)	1,108	2,370
Segment assets	329,250	352,848	329,250	352,848
Reportable Segment [Member] | Enterprise Connectivity Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues	160,401	161,827	296,293	303,608
Affiliate revenues	1,328	1,708	3,027	3,680
Segment EBITDA	29,575	29,792	53,311	49,801
Depreciation expense	3,429	3,180	6,818	6,394
Amortization expense	432	429	861	861
Severance, restructuring, and acquisition integration costs	1,207	83	1,707	651
Segment assets	253,424	279,360	253,424	279,360
Reportable Segment [Member] | Industrial Connectivity Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues	147,808	160,875	288,899	313,847
Affiliate revenues	214	408	396	731
Segment EBITDA	27,064	28,680	50,051	52,853
Depreciation expense	2,709	2,869	5,427	5,720
Amortization expense	601	807	1,192	1,630
Severance, restructuring, and acquisition integration costs	2,371	1,163	3,236	2,936
Purchase accounting effects of acquisitions				267
Segment assets	255,250	267,448	255,250	267,448
Reportable Segment [Member] | Industrial IT Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues	62,510	61,270	116,392	122,343
Affiliate revenues	4	10	32	31
Segment EBITDA	12,676	10,178	21,285	21,265
Depreciation expense	660	584	1,184	1,143
Amortization expense	1,506	1,479	3,016	2,889
Severance, restructuring, and acquisition integration costs	943		3,608	(52)
Segment assets	65,603	63,599	65,603	63,599
Reportable Segment [Member] | Network Security Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues	39,141	39,618	80,804	76,743
Affiliate revenues				8
Segment EBITDA	9,515	8,772	20,982	18,673
Depreciation expense	1,128	919	2,198	1,863
Amortization expense	10,304	10,607	20,375	22,020
Severance, restructuring, and acquisition integration costs	29	378	29	1,045
Purchase accounting effects of acquisitions				9,155
Deferred gross profit adjustments	1,256	14,364	2,945	32,728
Segment assets	$ 41,573	$ 42,241	$ 41,573	$ 42,241