XML 63 R48.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Acquisitions Of Businesses (Details) $ in Thousands |  |  |  |  |  |  |  |  | 10 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Nov. 01, 2017 Company | Mar. 01, 2017 Company | Jan. 04, 2017 Company | Apr. 15, 2016 USD ($) Company | Apr. 01, 2016 Company | Oct. 19, 2015 Company | Oct. 13, 2015 Company | Jun. 01, 2015 Company | Nov. 01, 2017 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($)
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Goodwill |  |  |  |  |  |  |  |  |  | $ 964,893 | $ 979,628 | $ 843,170
Amortization periods |  |  |  |  |  |  |  |  |  | 9 years 6 months |  |
Number of businesses acquired | Company | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |  |  |  |
2017Acquisitions [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Purchase price |  |  |  |  |  |  |  |  | $ 109,300 |  |  |
Working capital acquired |  |  |  |  |  |  |  |  |  | $ 9,800 |  |
Other net assets |  |  |  |  |  |  |  |  |  | 2,300 |  |
Goodwill |  |  |  |  |  |  |  |  |  | 40,600 |  |
Identifiable intangible assets |  |  |  |  |  |  |  |  |  | $ 56,600 |  |
Ardent [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business acquisition, percentage of voting interests acquired |  |  |  | 100.00% |  |  |  |  |  |  |  |
Purchase price |  |  |  | $ 201,400 |  |  |  |  |  |  |  |
Working capital acquired |  |  |  | 34,100 |  |  |  |  |  |  |  |
Other net assets |  |  |  | 3,900 |  |  |  |  |  |  |  |
Goodwill |  |  |  | 121,900 |  |  |  |  |  |  |  |
Identifiable intangible assets |  |  |  | 41,500 |  |  |  |  |  |  |  |
Acquired goodwill, tax deductible amount |  |  |  | $ 99,700 |  |  |  |  |  |  |  |
Amortization periods |  |  |  |  |  |  |  |  |  | 13 years 6 months |  |

X
- Definition The amount of acquisition cost of a business combination allocated to other net assets. + References No definition available. + Details
Name: | eme_BusinessCombinationRecognizedOtherNetAssets
Namespace Prefix: | eme_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of acquisition cost of a business combination allocated to working capital. + References No definition available. + Details
Name: | eme_BusinessCombinationRecognizedWorkingCapital
Namespace Prefix: | eme_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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 Percentage of voting equity interests acquired at the acquisition date in the business combination. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463 + Details
Name: | us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 + Details
Name: | us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of intangible assets, excluding goodwill, acquired at the acquisition date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
Name: | us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The number of businesses acquired by the entity during the period. + References No definition available. + Details
Name: | us-gaap_NumberOfBusinessesAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=eme_A2017AcquisitionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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