Segment Reporting - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting [Abstract]
Asset optimization revenue	$ 32.7	$ 39.2	$ 110.9	$ 101.1
Asset optimization cost of revenues	$ 31.9	$ 39.4	$ 107.4	$ 101.5