XML 67 R40.htm IDEA: XBRL DOCUMENT
v3.19.3

Revenue from Contracts with Customers (Details) - USD ($) | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018
Business Acquisition [Line Items] |  |  |  |  |
Performance obligation satisfied in previous period | $ 0 | $ 6,300,000.0 | $ 0 | $ 6,300,000 |
Change in estimate of transaction price | 0 | 0 | 0 | 0 |
Change in total estimated cost | 0 | $ 4,700,000 | 0 | $ 5,500,000 |
Loss on contracts | 0 |  | 0 |  |
Change in net contract liabilities |  |  | 7,100,000 |  |
Contract asset impairment |  |  | 0 |  | $ 0
Remaining performance obligations | $ 4,035,088,000 |  | 4,035,088,000 |  |
2019 Acquisitions |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |
Increase in contract assets from acquisitions |  |  | 6,200,000 |  |
Increase in contract liabilities from acquisitions |  |  | $ 13,000,000.0 |  |

X
- Definition Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in measure of progress which increases (decreases) right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time. + References No definition available. + Details
Name: | eme_ContractWithCustomerCumulativeCatchUpAdjustmentToRevenueChangeInMeasureOfProgress
Namespace Prefix: | eme_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) in net contract assets and liabilities. + References No definition available. + Details
Name: | eme_ContractwithCustomerAssetsandLiabilitiesNetChange
Namespace Prefix: | eme_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expense (reversal of expense) for expected credit loss on right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130551-203045 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045 + Details
Name: | us-gaap_ContractWithCustomerAssetCreditLossExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from change in estimate of transaction price which increases (decreases) right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time. Includes, but is not limited to, change in assessment of whether estimate of variable consideration is constrained. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130551-203045 + Details
Name: | us-gaap_ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase (decrease) in right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, from business combination. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130551-203045 + Details
Name: | us-gaap_ContractWithCustomerAssetIncreaseDecreaseForContractAcquiredInBusinessCombination
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) in obligation to transfer good or service to customer for which consideration from customer has been received or is due, from business combination. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130551-203045 + Details
Name: | us-gaap_ContractWithCustomerLiabilityIncreaseDecreaseForContractAcquiredInBusinessCombination
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of revenue recognized from performance obligation satisfied or partially satisfied in previous reporting periods. Includes, but is not limited to, change in transaction price. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 12A -URI http://asc.fasb.org/extlink&oid=118956577&loc=SL108322424-203045 + Details
Name: | us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- 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. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.2) -URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 605 -SubTopic 35 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=68068069&loc=d3e57763-111642 + Details
Name: | us-gaap_LossOnContracts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of transaction price allocated to performance obligation that has not been recognized as revenue. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 13 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130556-203045 + Details
Name: | us-gaap_RevenueRemainingPerformanceObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=eme_A2019AcquisitionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |