Severance, Restructuring, and Acquisition Integration Activities Severance, Restructuring, and Acquisition Integration Activities - Severance, Restructuring and Integration Costs by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Severance	$ 3,051	$ 20,754	$ 788
Other Restructuring and Integration Costs	9,207	5,790	21,837
Total Costs	12,258	26,544	22,625
FutureLink, Opterna, and SPC Integration Program
Restructuring Cost and Reserve [Line Items]
Total Costs	4,900	6,100
Enterprise Solutions
Restructuring Cost and Reserve [Line Items]
Severance	1,345	5,018	548
Other Restructuring and Integration Costs	6,374	5,790	14,315
Total Costs	7,719	10,808	14,863
Industrial Solutions
Restructuring Cost and Reserve [Line Items]
Severance	1,706	15,736	240
Other Restructuring and Integration Costs	2,833	0	7,522
Total Costs	$ 4,539	$ 15,736	$ 7,762