Revisions in Estimates (Tables)

12 Months Ended

Dec. 31, 2012

Construction [Member]

Change in Accounting Estimate [Line Items]

Schedule of Change in Accounting Estimate

Decreases



Years Ended December 31,		2012		2011		2010
Number of projects with downward estimate changes		9		4		5
Range of reduction in gross profit from each project, net	$	1.0 - 6.6	$	1.4 - 2.6	$	1.1 - 2.5
Decrease on project profitability	$	26.2	$	7.4	$	8.7

Increases



Years Ended December 31,		2012		2011		2010
Number of projects with upward estimate changes		6		7		6
Range of increase in gross profit from each project, net	$	1.0 - 1.7	$	1.0 - 3.5	$	1.0 - 4.2
Increase on project profitability	$	8.1	$	13.6	$	12.6

Large Project Construction [Member]

Change in Accounting Estimate [Line Items]

Schedule of Change in Accounting Estimate

Decreases



Years Ended December 31,		2012		2011		2010
Number of projects with downward estimate changes		1		5		2
Range of reduction in gross profit from each project, net	$	27.4	$	1.2 - 5.1	$	1.8 - 10.2
Decrease on project profitability	$	27.4	$	19.4	$	12.0

Increases



Years Ended December 31,		2012		2011		2010
Number of projects with upward estimate changes		10		9		6
Range of increase in gross profit from each project, net	$	1.1 - 24.5	$	1.1 - 6.9	$	1.1 - 4.8
Increase on project profitability	$	92.0	$	28.3	$	18.0

The following table presents additional information about four of the projects with significant upward changes in 2012 (dollars in millions):



Years Ended December 31,	Number of Projects	Total Contract Value		2012 Gross Profit Increase Impact	Backlog at December 31, 2012	Percent of Total Large Project Construction Backlog at December 31, 2012
Projects less than 90% complete	2	$	721.3	38.5	199.6	18.5	%
Projects greater than 90% complete	2	432.0		39.7	24.6	2.3	%
Total for projects with significant upward changes	4	$	1,153.3	78.2	224.2	20.8	%

- Definition

Tabular disclosure of the change in an accounting estimate, including a change that occurs in an interim period. If a change in accounting estimate affects several future periods (for example, a change in the service life of a depreciable asset) disclose the effect on income from continuing operations, net income (or other appropriate captions of changes in the applicable net assets or performance indicator), and any related per-share amounts of the current period. Disclosure of the effects of a change in an accounting estimate that occurs in the ordinary course of business (such as uncollectible accounts or inventory obsolescence) is not required, unless the effect is material.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 270

-SubTopic 10

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-URI http://asc.fasb.org/extlink&oid=6958853&loc=d3e46468-122699

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 28

-Paragraph 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 250

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6801783&loc=d3e22595-107794

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 154

-Paragraph 22

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 270

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=6372559&loc=d3e777-108305

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 250

-SubTopic 10

-Section 45

-Paragraph 18

-URI http://asc.fasb.org/extlink&oid=6368906&loc=d3e21843-107793

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 01

-Paragraph a

-Subparagraph 5

-Article 10

+ Details