Segment Information (Details) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) location segment	Jun. 30, 2018 USD ($)
Segment Information
Number of reportable segments \| segment			2
Number or operating locations \| location			36
Revenues	$ 650,302	$ 535,043	$ 1,188,775	$ 999,984
Gross profit	120,016	111,183	226,681	200,236
Operating \| Mechanical Services
Segment Information
Revenues	553,031	535,043	1,087,616	999,984
Gross profit	110,279	$ 111,183	216,131	$ 200,236
Operating \| Electrical Services
Segment Information
Revenues	97,271		101,159
Gross profit	$ 9,737		$ 10,550

The number of operating locations.

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- Definition

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

+ References

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-Name Accounting Standards Codification
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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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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.

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