Revisions in Estimates

Our profit recognition related to construction contracts is based on estimates of costs to complete each project. These estimates can vary in the normal course of business as projects progress and uncertainties are resolved. We do not recognize revenue on contract change orders or claims until we have a signed agreement; however, we do recognize costs as incurred and revisions to estimated total costs as soon as the obligation to perform is determined. Approved change orders and claims, as well as changes in related estimates of costs to complete, are considered revisions in estimates. We use the cumulative catch-up method applicable to construction contract accounting to account for revisions in estimates. Under this method, revisions in estimates are accounted for in their entirety in the period of change. As of March 31, 2013, we had no revisions in estimates that are reasonably certain to impact future periods.

Construction

There were no revisions in estimates, either increases or decreases, that individually had an impact of $1.0 million or more on gross profit during the three months ended March 31, 2013. The net change in project profitability from revisions in estimates, both increases and decreases, that individually had an impact of $1.0 million or more on gross profit for the three months ended March 31, 2012 was a net decrease of $0.2 million. The projects are summarized as follows:

Increases



	Three Months Ended March 31,
(dollars in millions)			2013		2012
Number of projects with upward estimate changes			—		2
Range of increase in gross profit from each project, net		$	—	$	1.0 - 1.8
Increase on project profitability		$	—	$	2.8

The increases during the three months ended March 31, 2012 were due to lower than anticipated costs and settlement of outstanding issues with contract owners.

Decreases



	Three Months Ended March 31,
(dollars in millions)			2013		2012
Number of projects with downward estimate changes			—		1
Reduction in gross profit from each project, net		$	—	$	3.0
Decrease on project profitability		$	—	$	3.0

The decrease during the three months ended March 31, 2012 was due to lower productivity than originally anticipated.

Large Project Construction

The net changes in project profitability from revisions in estimates, both increases and decreases, that individually had an impact of $1.0 million or more on gross profit were net increases of $9.2 million and $4.4 million for the three months ended March 31, 2013 and 2012, respectively. Amounts attributable to noncontrolling interests were $1.7 million and $1.3 million of the net increases for the three months ended March 31, 2013 and 2012, respectively. The projects are summarized as follows:

Increases



	Three Months Ended March 31,
(dollars in millions)			2013		2012
Number of projects with upward estimate changes			3		4
Range of increase in gross profit from each project, net		$	1.9 - 7.8	$	1.6 - 2.4
Increase on project profitability		$	16.1	$	8.1

The increases during the three months ended March 31, 2013 were due to lower than anticipated construction costs and resolution of project uncertainties. The increases during the three months ended March 31, 2012 were due to owner directed scope changes and lower than anticipated construction costs.

Decreases



	Three Months Ended March 31,
(dollars in millions)			2013		2012
Number of projects with downward estimate changes			2		2
Range of reduction in gross profit from each project, net		$	2.4 - 4.5	$	1.5 - 2.2
Decrease on project profitability		$	6.9	$	3.7

The downward estimate changes during the three months ended March 31, 2013 were due to higher than anticipated costs. The downward estimate changes during the three months ended March 31, 2012 were due to lower productivity than anticipated.