Operating Segments and Geographic Information - Operating Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Depreciation expense									$ 45,600	$ 47,200	$ 46,600
Amortization of intangibles									103,997	98,385	103,791
Severance, restructuring, and acquisition integration costs	$ 9,900	$ 16,700	$ 9,600	$ 6,600	$ 11,700	$ 12,800	$ 5,900	$ 8,400	42,790	38,770	47,170
Patent settlement					(10,300)
Acquisition of property, plant and equipment									64,261	53,974	54,969
Segment assets	3,840,613				3,806,803				3,840,613	3,806,803	3,290,602
Broadcast Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs									5,532	10,414	39,078
Enterprise Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs									23,511	11,962	723
Industrial Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs									12,272	9,923	6,228
Network Solutions [Member]
Segment Reporting Information [Line Items]
Severance, restructuring, and acquisition integration costs									1,475	6,471	1,141
Reportable Segment [Member]
Segment Reporting Information [Line Items]
Segment revenues									2,388,643	2,357,805	2,360,583
Affiliate revenues									9,362	8,125	7,929
Segment EBITDA									430,034	433,189	401,666
Depreciation expense									45,597	47,208	46,551
Amortization of intangibles									103,997	98,385	103,791
Severance, restructuring, and acquisition integration costs									42,790	38,770	47,170
Purchase accounting effects of acquisitions									6,133	(2,079)	9,747
Deferred gross profit adjustments									0	6,687	52,876
Patent settlement									0	(5,554)	0
Acquisition of property, plant and equipment									62,759	53,582	53,572
Segment assets	1,146,395				913,998				1,146,395	913,998	934,280
Reportable Segment [Member] | Broadcast Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues									725,139	769,753	739,970
Affiliate revenues									440	744	916
Segment EBITDA									112,849	137,870	113,638
Depreciation expense									15,763	16,229	16,295
Amortization of intangibles									49,325	47,248	49,812
Severance, restructuring, and acquisition integration costs									5,532	10,414	39,078
Purchase accounting effects of acquisitions									6,133	(2,991)	132
Deferred gross profit adjustments									0	1,774	2,446
Patent settlement									0	(5,554)	0
Acquisition of property, plant and equipment									21,314	15,713	27,365
Segment assets	405,842				325,396				405,842	325,396	346,095
Reportable Segment [Member] | Enterprise Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues									631,166	603,188	605,910
Affiliate revenues									7,385	5,977	5,322
Segment EBITDA									103,650	101,298	100,214
Depreciation expense									10,509	13,226	12,591
Amortization of intangibles									1,729	1,718	1,720
Severance, restructuring, and acquisition integration costs									23,511	11,962	723
Purchase accounting effects of acquisitions									0	912	52
Acquisition of property, plant and equipment									28,126	22,679	10,323
Segment assets	282,072				246,564				282,072	246,564	238,400
Reportable Segment [Member] | Industrial Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues									628,458	585,476	603,350
Affiliate revenues									1,441	1,325	1,613
Segment EBITDA									119,642	101,248	99,941
Depreciation expense									12,968	11,038	11,235
Amortization of intangibles									2,571	2,394	3,154
Severance, restructuring, and acquisition integration costs									12,272	9,923	6,228
Purchase accounting effects of acquisitions									0	0	334
Acquisition of property, plant and equipment									8,151	10,486	8,836
Segment assets	300,172				226,306				300,172	226,306	231,265
Reportable Segment [Member] | Network Solutions [Member]
Segment Reporting Information [Line Items]
Segment revenues									403,880	399,388	411,353
Affiliate revenues									96	79	78
Segment EBITDA									93,893	92,773	87,873
Depreciation expense									6,357	6,715	6,430
Amortization of intangibles									50,372	47,025	49,105
Severance, restructuring, and acquisition integration costs									1,475	6,471	1,141
Purchase accounting effects of acquisitions									0	0	9,229
Deferred gross profit adjustments									0	4,913	50,430
Acquisition of property, plant and equipment									5,168	4,704	7,048
Segment assets	$ 158,309				$ 115,732				158,309	115,732	118,520
Software Development [Member] | Reportable Segment [Member]
Segment Reporting Information [Line Items]
Amortization of intangibles									56	0	0
Software Development [Member] | Reportable Segment [Member] | Broadcast Solutions [Member]
Segment Reporting Information [Line Items]
Amortization of intangibles									$ 56	$ 0	$ 0