Reportable Segments - Operating Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Segment revenues	$ 475,839	$ 533,098	$ 1,364,176	$ 1,581,590
Depreciation expense	10,500	10,000	31,100	30,000
Amortization of intangibles	16,104	19,026	48,306	56,258
Severance, restructuring, and acquisition integration costs	1,357	3,047	9,448	5,566
Segment assets	3,036,082		3,036,082		$ 3,406,759
Enterprise Solutions
Segment Reporting Information [Line Items]
Segment revenues	229,097	247,236	644,684	699,644
Severance, restructuring, and acquisition integration costs	1,337	3,047	6,310	5,566
Industrial Solutions
Segment Reporting Information [Line Items]
Segment revenues	246,742	285,862	719,492	881,946
Severance, restructuring, and acquisition integration costs	20	0	3,138	0
Reportable Segment
Segment Reporting Information [Line Items]
Segment revenues	475,839	533,098	1,364,176	1,581,590
Segment EBITDA	64,641	90,717	173,560	258,331
Depreciation expense	10,455	9,979	31,069	29,990
Amortization of intangibles	16,104	19,026	48,306	56,258
Amortization of software development intangible assets	529	85	1,245	207
Severance, restructuring, and acquisition integration costs	1,357	3,047	9,448	5,566
Purchase Accounting Effects, Acquisitions	0	(186)	125	532
Segment assets	1,005,252	1,018,726	1,005,252	1,018,726
Reportable Segment | Enterprise Solutions
Segment Reporting Information [Line Items]
Segment revenues	229,097	247,236	644,684	699,644
Segment EBITDA	26,250	35,868	73,193	93,074
Depreciation expense	5,005	4,919	15,208	14,576
Amortization of intangibles	5,408	6,269	16,266	16,694
Amortization of software development intangible assets	73	49	184	120
Severance, restructuring, and acquisition integration costs	1,337	3,047	6,310	5,566
Purchase Accounting Effects, Acquisitions		(186)	125	532
Segment assets	519,142	517,448	519,142	517,448
Reportable Segment | Industrial Solutions
Segment Reporting Information [Line Items]
Segment revenues	246,742	285,862	719,492	881,946
Segment EBITDA	38,391	54,849	100,367	165,257
Depreciation expense	5,450	5,060	15,861	15,414
Amortization of intangibles	10,696	12,757	32,040	39,564
Amortization of software development intangible assets	456	36	1,061	87
Severance, restructuring, and acquisition integration costs	20	0	3,138	0
Purchase Accounting Effects, Acquisitions		0	0	0
Segment assets	486,110	501,278	486,110	501,278
Affiliate revenues | Reportable Segment
Segment Reporting Information [Line Items]
Segment revenues	241	755	970	3,209
Affiliate revenues | Reportable Segment | Enterprise Solutions
Segment Reporting Information [Line Items]
Segment revenues	231	753	940	3,190
Affiliate revenues | Reportable Segment | Industrial Solutions
Segment Reporting Information [Line Items]
Segment revenues	$ 10	$ 2	$ 30	$ 19