Post Employment Plans - Contributions to the plans (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Jun. 27, 2015
Postemployment Benefits [Abstract]
Defined contribution plans cost	$ 18.9	$ 25.5	$ 26.1	$ 25.9	[1]

[1] Includes Omega activity from March 30, 2015 to June 27, 2015