Stockholders' Equity (Equity Stmt) (Details) $ / shares in Units, $ in Thousands			3 Months Ended		6 Months Ended
	Apr. 11, 2016 USD ($) shares	Jun. 24, 2015 USD ($) shares	Jun. 24, 2016 USD ($) $ / shares shares	Jun. 26, 2015 USD ($)	Jun. 24, 2016 USD ($) item $ / shares shares	Jun. 26, 2015 USD ($)	Dec. 25, 2015 $ / shares shares	Jun. 22, 2015 $ / shares shares
Stockholders Equity
Stockholders' equity beginning of period					$ 377,331
Shares purchased and retired					(73,885)
Shares issued in connection with stock-based compensation and employee benefit plans					18,277
Series A Preferred Stock, net of issuance costs					99,800
Net (loss) attributable to CH2M			$ (62,042)	$ 16,278	(37,463)	$ 39,776
Other comprehensive loss, net of tax			12,549	4,930	15,835	(7,610)
Loss attributable to noncontrolling interests			(92,148)	$ (644)	(93,003)	3,363
Investment in affiliates, net					45,879
Stockholders' equity end of period			$ 352,771		$ 352,771
Preferred stock, shares authorized | shares			50,000,000		50,000,000		50,000,000
Preferred stock, par value (in dollars per share) | $ / shares			$ 0.01		$ 0.01		$ 0.01
Proceeds from the issuance of preferred stock, net of issuance costs					$ 99,800	$ 192,377
Common Shares
Stockholders Equity
Stockholders' equity, beginning of period, (in shares) | shares					26,283,000
Shares purchased and retired (in shares) | shares					(1,172,000)
Shares issued in connection with stock-based compensation and employee benefit plans (in shares) | shares					303,000
Stockholders' equity, end of period (in shares) | shares			25,414,000		25,414,000
Series A Preferred Stock
Stockholders Equity
Stockholders' equity, beginning of period, (in shares) | shares					3,214,000
Series A Preferred Stock, net of issuance costs (in shares) | shares					1,608,000
Stockholders' equity, end of period (in shares) | shares			4,822,000		4,822,000
Preferred stock, shares authorized | shares			10,000,000		10,000,000		10,000,000	10,000,000
Original issue price of share (in dollars per share) | $ / shares								$ 62.22
Annual dividend rate					5.00%
Conversion price (in dollars per share) | $ / shares					$ 62.22
Series A Preferred Stock | Maximum
Stockholders Equity
Redemption price of preferred stock			$ 600,000		$ 600,000
Series A Preferred Stock | Minimum
Stockholders Equity
Threshold for conversion					200,000
Authorized amount for investment			$ 100,000		$ 100,000
Series A Preferred Stock | Future plan
Stockholders Equity
Number of installments for stock redemption | item					1
Series A Preferred Stock | Future plan | Sale Recommended Stockholders Not Approve
Stockholders Equity
Conversion price (in dollars per share) | $ / shares					$ 52.65
Series A Preferred Stock | Future plan | Recommended Sale And Certain Other Actions To Facilitate Initial Public Offering Not Approved
Stockholders Equity
Conversion price (in dollars per share) | $ / shares					$ 47.86
Series A Preferred Stock | Future plan | Maximum
Stockholders Equity
Annual dividend rate					15.00%
Series A Preferred Stock | Future plan | Minimum
Stockholders Equity
Annual dividend rate					10.00%
Series A Preferred Stock | Apollo Global Management, LLC
Stockholders Equity
Series A Preferred Stock, net of issuance costs	$ 100,000	$ 200,000
Series A Preferred Stock, net of issuance costs (in shares) | shares	1,607,200	3,214,400
Proceeds from the issuance of preferred stock, net of issuance costs	$ 99,800	$ 191,700
Issuance cost	$ 200	$ 8,300
Series A Preferred Stock | Apollo Global Management, LLC | Maximum
Stockholders Equity
Consolidated leverage ratio					3.00