Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 25, 2015	Sep. 30, 2016	Sep. 25, 2015
Net income (loss) attributable to CH2M per common share1:
Income allocated to preferred stockholders	$ 1,984	$ 3,913		$ 2,502
Accrued dividends attributable to preferred stockholders	3,891	2,501	$ 10,067	2,556
Preferred Stock
Net income (loss) attributable to CH2M per common share1:
Income allocated to preferred stockholders	1,984	3,913		2,502
Accrued dividends attributable to preferred stockholders	$ 3,891	$ 2,501	$ 10,067	$ 2,556