Revisions in Estimates (Tables)

6 Months Ended

Jun. 30, 2017

Construction [Member]

Change in Accounting Estimate [Line Items]

Schedule of Change in Accounting Estimate

The projects are summarized as follows:

Decreases

	Three Months Ended June 30,					Six Months Ended June 30,
(dollars in millions)		2017		2016		2017		2016
Number of projects with downward estimate changes		1		1		1		2
Range of reduction in gross profit from each project, net	$	1.1	$	1.0	$	1.8	$	1.2 - 1.3
Decrease on project profitability	$	1.1	$	1.0	$	1.8	$	2.5

Large Project Construction [Member]

Change in Accounting Estimate [Line Items]

Schedule of Change in Accounting Estimate

Decreases

	Three Months Ended June 30,					Six Months Ended June 30,
(dollars in millions)		2017		2016		2017		2016
Number of projects with downward estimate changes		5		4		7		4
Range of reduction in gross profit from each project, net	$	1.1 - 8.1	$	2.2 - 5.9	$	1.0 - 10.8	$	3.4 - 6.4
Decrease on project profitability	$	23.8	$	14.6	$	37.8	$	20.1

The projects are summarized as follows:

Increases

	Three Months Ended June 30,					Six Months Ended June 30,
(dollars in millions)		2017		2016		2017		2016
Number of projects with upward estimate changes		—		2		—		4
Range of increase in gross profit from each project, net	$	—	$	2.9 - 6.9	$	—	$	1.2 - 6.9
Increase on project profitability	$	—	$	9.8	$	—	$	12.3