Segment Information (Narrative) (Details)	3 Months Ended
	Dec. 29, 2017 USD ($)	Mar. 31, 2017 USD ($)	Apr. 01, 2016 Business
Segment Reporting Information [Line Items]
Number of operating and reporting structure of business | Business			4
Restructuring pre-tax net charges		$ 22,600
CH2M HILL Companies, Ltd.
Segment Reporting Information [Line Items]
Restructuring pre-tax net charges	$ 19,300,000