Revenue (Tables)

3 Months Ended

Mar. 31, 2019

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue by Timing

The following table represents a disaggregation of revenue by timing of revenue along with the reportable segment for each category:

	Three Months Ended March 31, 2019
	Energy & Chemicals		D&S West		D&S East		Intersegment Eliminations			Consolidated
Point in time	$	74.1	$	107.4	$	63.9	$	(3.0	)	$	242.4
Over time	31.5		10.6		4.8		—			46.9
Total	$	105.6	$	118.0	$	68.7	$	(3.0	)	$	289.3

	Three Months Ended March 31, 2018
	Energy & Chemicals		D&S West		D&S East		Intersegment Eliminations			Consolidated
Point in time	$	23.9	$	91.3	$	50.5	$	(1.5	)	$	164.2
Over time	66.0		9.3		4.6		—			79.9
Total	$	89.9	$	100.6	$	55.1	$	(1.5	)	$	244.1

Refer to Note 3, “Reportable Segments,” for a table of revenue disaggregated by product application along with the reportable segment for each category.

Changes in Contract Assets and Contract Liabilities Balances

The following table represents changes in our contract assets and contract liabilities balances:

	March 31, 2019		December 31, 2018		Year-to-date Change ($)			Year-to-date Change (%)
Contract assets
Accounts receivable, net of allowances	$	205.2	$	194.8	10.4			5.3	%
Unbilled contract revenue	68.9		54.5		14.4			26.4	%
Contract liabilities
Customer advances and billings in excess of contract revenue	$	129.5	$	130.0	$	(0.5	)	(0.4	)%
Long-term deferred revenue	1.3		1.4		(0.1		)	(7.1	)%