RESTRUCTURING AND ASSET IMPAIRMENTS - Restructuring Costs by Classification on the Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 559	$ 1,549
Cost of services provided and products sold (excluding amortization of intangible assets)
Restructuring Cost and Reserve [Line Items]
Restructuring costs	476	1,416
Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring costs	83	133
Severance and Transition Costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs	330	400
Severance and Transition Costs | Cost of services provided and products sold (excluding amortization of intangible assets)
Restructuring Cost and Reserve [Line Items]
Restructuring costs	247	267
Severance and Transition Costs | Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring costs	83	133
Asset Impairments and Other Costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs	229	1,149
Asset Impairments and Other Costs | Cost of services provided and products sold (excluding amortization of intangible assets)
Restructuring Cost and Reserve [Line Items]
Restructuring costs	229	1,149
Asset Impairments and Other Costs | Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 0	$ 0