Operating Segments - Operating Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Depreciation expense	$ 11,400	$ 11,700
Amortization expense	23,669	25,532
Severance, restructuring, and acquisition integration costs	6,600	8,408
Segment assets	3,787,641		$ 3,806,803
Broadcast Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs	408	4,378
Enterprise Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs	4,873	500
Industrial Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs	1,121	865
Reportable Segment [Member]
Segment Reporting Information [Line Items]
Segment revenues	551,381	543,800
Affiliate revenues	3,106	2,333
Segment EBITDA	93,110	90,066
Depreciation expense	11,383	11,663
Amortization expense	23,669	25,532
Severance, restructuring, and acquisition integration costs	6,600	8,408
Purchase accounting effects of acquisitions	0	195
Deferred gross profit adjustments	0	2,303
Segment assets	940,712	919,853
Reportable Segment [Member] | Broadcast Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues	168,596	171,272
Affiliate revenues	101	424
Segment EBITDA	25,400	23,267
Depreciation expense	3,949	3,962
Amortization expense	10,015	12,931
Severance, restructuring, and acquisition integration costs	408	4,378
Purchase accounting effects of acquisitions		195
Deferred gross profit adjustments		614
Segment assets	321,342	332,009
Reportable Segment [Member] | Enterprise Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues	145,682	135,892
Affiliate revenues	2,558	1,699
Segment EBITDA	24,100	23,736
Depreciation expense	2,599	3,389
Amortization expense	424	429
Severance, restructuring, and acquisition integration costs	4,873	500
Purchase accounting effects of acquisitions		0
Deferred gross profit adjustments		0
Segment assets	250,198	233,422
Reportable Segment [Member] | Industrial Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues	146,181	141,091
Affiliate revenues	387	182
Segment EBITDA	25,733	22,987
Depreciation expense	3,206	2,718
Amortization expense	642	591
Severance, restructuring, and acquisition integration costs	1,121	865
Purchase accounting effects of acquisitions		0
Deferred gross profit adjustments		0
Segment assets	264,016	248,971
Reportable Segment [Member] | Network Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues	90,922	95,545
Affiliate revenues	60	28
Segment EBITDA	17,877	20,076
Depreciation expense	1,629	1,594
Amortization expense	12,588	11,581
Severance, restructuring, and acquisition integration costs	198	2,665
Purchase accounting effects of acquisitions		0
Deferred gross profit adjustments		1,689
Segment assets	$ 105,156	$ 105,451