Summary of Significant Accounting Policies - Revenue Recognition (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
Dec. 31, 2016 |
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| Revenue Recognition [Line Items] | |||||
| Percent increase (decrease) in operating results due to change in contract estimates | 10.20% | (9.20%) | (6.70%) | ||
| Change in contract estimates | $ 24.6 | ||||
| Change orders and/or claims | $ 118.9 | $ 118.9 | $ 137.8 | ||
| Maximum | |||||
| Revenue Recognition [Line Items] | |||||
| Percent aggregate change in contract estimates impact on operating results is less than this percentage | 5.00% | ||||
| Alaska Power Plant Construction Project | |||||
| Revenue Recognition [Line Items] | |||||
| Losses on contracts | $ 30.5 | $ 51.8 | |||
| X | ||||||||||
- Definition Change In Contract Estimates, Impact On Operating Results, Gains No definition available.
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- Definition Change In Contract Estimates Positive (Negative) Impact On Operating Results No definition available.
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- Definition Percent aggregate change in contract estimates impact on operating results is less than this percentage. No definition available.
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- Definition Revenue recognition. No definition available.
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- Definition Losses recognized in the current period on contracts which are expected to generate losses, which are probable and can be reasonably estimated, in a future period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The amount of costs incurred on unapproved change orders when it is probable that the cost will be recovered through a change in the contract price. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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