Revisions in Estimates (Tables)

9 Months Ended

Sep. 30, 2017

Construction [Member]

Change in Accounting Estimate [Line Items]

Schedule of Change in Accounting Estimate

The projects are summarized as follows:

Increases

	Three Months Ended September 30,					Nine Months Ended September 30,
(dollars in millions)		2017		2016		2017		2016
Number of projects with upward estimate changes		2		1		5		2
Range of increase in gross profit from each project, net	$	1.0 - 1.2	$	2.6	$	1.0 - 1.6	$	1.8 - 2.7
Increase on project profitability	$	2.2	$	2.6	$	6.0	$	4.5

Decreases

	Three Months Ended September 30,					Nine Months Ended September 30,
(dollars in millions)		2017		2016		2017		2016
Number of projects with downward estimate changes		1		1		3		5
Range of reduction in gross profit from each project, net	$	2.5	$	1.9	$	1.1 - 3.5	$	1.1 - 2.6
Decrease on project profitability	$	2.5	$	1.9	$	7.3	$	7.6

Large Project Construction [Member]

Change in Accounting Estimate [Line Items]

Schedule of Change in Accounting Estimate

The projects are summarized as follows:

Increases

	Three Months Ended September 30,					Nine Months Ended September 30,
(dollars in millions)		2017		2016		2017		2016
Number of projects with upward estimate changes		—		3		—		7
Range of increase in gross profit from each project, net	$	—	$	1.4 - 3.0	$	—	$	1.2 - 6.5
Increase on project profitability	$	—	$	6.1	$	—	$	19.8

Decreases

	Three Months Ended September 30,					Nine Months Ended September 30,
(dollars in millions)		2017		2016		2017		2016
Number of projects with downward estimate changes		3		3		7		4
Range of reduction in gross profit from each project, net	$	2.4 - 12.7	$	1.1 - 3.5	$	1.3 - 14.5	$	3.4 - 7.9
Decrease on project profitability	$	19.3	$	5.7	$	58.1	$	25.8