Summary of Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2015
Accounting Policies [Abstract]
Fair Value Measurements	We use a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy, which gives the highest priority to quoted prices in active markets, is comprised of the following three levels: Level 1 – Unadjusted quoted market prices in active markets for identical assets and liabilities. Level 2 – Observable inputs, other than Level 1 inputs. Level 2 inputs would typically include quoted prices in markets that are not active or financial instruments for which all significant inputs are observable, either directly or indirectly. Level 3 – Prices or valuations that require inputs that are both significant to the measurement and unobservable.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its majority-owned subsidiaries and joint ventures. Significant intercompany accounts and transactions have been eliminated. All investments over which we exercise significant influence, but do not control (a 20% to 50% ownership interest), are accounted for using the equity method of accounting. Additionally, we participate in a joint venture with another company, and we have consolidated this joint venture as we have determined that through our participation we have a variable interest and are the primary beneficiary as defined by the Financial Accounting Standards Board (“FASB”) Accounting Standard Codification (“ASC”) Topic 810, “Consolidation”. For joint ventures that have been accounted for using the consolidation method of accounting, noncontrolling interest represents the allocation of earnings to our joint venture partners who either have a minority-ownership interest in the joint venture or are not at risk for the majority of losses of the joint venture. The results of operations of companies acquired have been included in the results of operations from the date of the respective acquisition.
Principles of Preparation	Principles of Preparation The preparation of the consolidated financial statements, in conformity with accounting principles generally accepted in the United States, requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could materially differ from those estimates.
Revenue Recognition	Revenue Recognition Revenues from long-term construction contracts are recognized on the percentage-of-completion method in accordance with ASC Topic 605-35, “Revenue Recognition-Construction-Type and Production-Type Contracts”. Percentage-of-completion is measured principally by the percentage of costs incurred to date for each contract to the estimated total costs for such contract at completion. Certain of our electrical contracting business units measure percentage-of-completion by the percentage of labor costs incurred to date for each contract to the estimated total labor costs for such contract. Pre-contract costs from our construction projects are generally expensed as incurred. Revenues from the performance of services for maintenance, repair and retrofit work are recognized consistent with the performance of the services, which are generally on a pro-rata basis over the life of the contractual arrangement. Expenses related to all services arrangements are recognized as incurred. Revenues related to the engineering, manufacturing and repairing of shell and tube heat exchangers are recognized when the product is shipped and all other revenue recognition criteria have been met. Costs related to this work are included in inventory until the product is shipped. In the case of customer change orders for uncompleted long-term construction contracts, estimated recoveries are included for work performed in forecasting ultimate profitability on certain contracts. Due to uncertainties inherent in the estimation process, it is possible that completion costs, including those arising from contract penalty provisions and final contract settlements, will be revised in the near-term. Such revisions to costs and income are recognized in the period in which the revisions are determined. Provisions for the entirety of estimated losses on uncompleted contracts are made in the period in which such losses are determined.
Costs and estimated earnings on uncompleted contracts	Costs and estimated earnings on uncompleted contracts Costs and estimated earnings in excess of billings on uncompleted contracts arise in the consolidated balance sheets when revenues have been recognized but the amounts cannot be billed under the terms of the contracts. Such amounts are recoverable from customers upon various measures of performance, including achievement of certain milestones, completion of specified units, or completion of a contract. Also included in costs and estimated earnings on uncompleted contracts are amounts we seek or will seek to collect from customers or others for errors or changes in contract specifications or design, contract change orders in dispute or unapproved as to both scope and/or price or other customer-related causes of unanticipated additional contract costs (claims and unapproved change orders). Such amounts are recorded at estimated net realizable value when realization is probable and can be reasonably estimated. No profit is recognized on construction costs incurred in connection with claim amounts. Claims and unapproved change orders made by us involve negotiation and, in certain cases, litigation. In the event litigation costs are incurred by us in connection with claims or unapproved change orders, such litigation costs are expensed as incurred, although we may seek to recover these costs. We believe that we have established legal bases for pursuing recovery of our recorded unapproved change orders and claims, and it is management’s intention to pursue and litigate such claims, if necessary, until a determination or settlement is reached. Unapproved change orders and claims also involve the use of estimates, and it is reasonably possible that revisions to the estimated recoverable amounts of recorded claims and unapproved change orders may be made in the near term. If we do not successfully resolve these matters, a net expense (recorded as a reduction in revenues) may be required, in addition to amounts that may have been previously provided for. We record the profit associated with the settlement of claims upon receipt of final payment. During 2015, we recognized revenues of $12.1 million as a result of the settlement of a claim within our United States mechanical construction and facilities services segment, which represents the recovery of cost on a project in which we incurred significant losses in a prior year. There were no significant settlements or payment of claims in 2014. Claims against us are recognized when a loss is considered probable and amounts are reasonably determinable.
Classification of Contract Amounts	Classification of Contract Amounts In accordance with industry practice, we classify as current all assets and liabilities relating to the performance of long-term contracts. The term of our contracts ranges from one month to four years and, accordingly, collection or payment of amounts relating to these contracts may extend beyond one year.
Cash and cash equivalents	Cash and cash equivalents For purposes of the consolidated financial statements, we consider all highly liquid instruments with original maturities of three months or less to be cash equivalents. We maintain a centralized cash management system whereby our excess cash balances are invested in high quality, short-term money market instruments, which are considered cash equivalents. We have cash balances in certain of our domestic bank accounts that exceed federally insured limits.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts Accounts receivable are recorded at the invoiced amount and do not bear interest. The Company maintains an allowance for doubtful accounts. This allowance is based upon the best estimate of the probable losses in existing accounts receivable. The Company determines the allowances based upon individual accounts when information indicates the customers may have an inability to meet their financial obligations, as well as historical collection and write-off experience. These amounts are re-evaluated and adjusted on a regular basis as additional information is received. Actual write-offs are charged against the allowance when collection efforts have been unsuccessful.
Inventories	Inventories Inventories are stated at the lower of cost or market. Cost is determined principally using the average cost method.
Property, plant and equipment	Property, plant and equipment Property, plant and equipment is stated at cost. Depreciation, including amortization of assets under capital leases, is recorded principally using the straight-line method over estimated useful lives of 3 to 10 years for machinery and equipment, 3 to 7 years for vehicles, furniture and fixtures and computer hardware/software and 25 years for buildings. Leasehold improvements are amortized over the shorter of the remaining life of the lease term or the expected service life of the improvement. The carrying values of property, plant and equipment are reviewed for impairment whenever facts and circumstances indicate that the carrying amount may not be fully recoverable. In performing this review for recoverability, property, plant and equipment is assessed for possible impairment by comparing their carrying values to their undiscounted net pre-tax cash flows expected to result from the use of the asset. Impaired assets are written down to their fair values, generally determined based on their estimated future discounted cash flows.
Goodwill and Identifiable Intangible Assets	Goodwill and Identifiable Intangible Assets Goodwill and other identifiable intangible assets with indefinite lives that are not being amortized, such as trade names, are tested at least annually for impairment (which we test each October 1, absent any impairment indicators) and are written down if impaired. Identifiable intangible assets with finite lives are amortized over their useful lives and are reviewed for impairment whenever facts and circumstances indicate that their carrying values may not be fully recoverable. See Note 8 - Goodwill and Identifiable Intangible Assets of the notes to consolidated financial statements for additional information.
Insurance Liabilities	Insurance Liabilities Our insurance liabilities are determined actuarially based on claims filed and an estimate of claims incurred but not yet reported.
Foreign Operations	Foreign Operations The financial statements and transactions of our foreign subsidiaries are maintained in their functional currency and translated into U.S. dollars in accordance with ASC Topic 830, “Foreign Currency Matters”. Translation adjustments have been recorded as “Accumulated other comprehensive loss”, a separate component of “Equity”.
Income Taxes	Income Taxes We account for income taxes in accordance with the provisions of ASC Topic 740, “Income Taxes” (“ASC 740”). ASC 740 requires an asset and liability approach which requires the recognition of deferred income tax assets and deferred income tax liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of assets and liabilities. Valuation allowances are established when necessary to reduce deferred income tax assets when it is more likely than not that a tax benefit will not be realized. We account for uncertain tax positions in accordance with the provisions of ASC 740. We recognize accruals of interest related to unrecognized tax benefits as a component of the income tax provision.
Valuation of Share-based Compensation Plans	Valuation of Share-Based Compensation Plans We have various types of share-based compensation plans and programs, which are administered by our Board of Directors or its Compensation and Personnel Committee. See Note 13 - Share-Based Compensation Plans of the notes to consolidated financial statements for additional information regarding the share-based compensation plans and programs. We account for share-based payments in accordance with the provisions of ASC Topic 718, “Compensation-Stock Compensation” (“ASC 718”). ASC 718 requires that all share-based payments issued to acquire goods or services, including grants of employee stock options, be recognized in the statement of operations based on their fair values, net of estimated forfeitures. ASC 718 requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Compensation expense related to share-based awards is recognized over the requisite service period, which is generally the vesting period. For shares subject to graded vesting, our policy is to apply the straight-line method in recognizing compensation expense. ASC 718 requires the benefits of tax deductions in excess of recognized compensation expense to be reported as a financing cash inflow, rather than as an operating cash inflow in the Consolidated Statements of Cash Flows. This requirement reduces net operating cash flows and increases net financing cash flows.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2015

We use a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy, which gives the highest priority to quoted prices in active markets, is comprised of the following three levels:

Level 1 – Unadjusted quoted market prices in active markets for identical assets and liabilities.

Level 2 – Observable inputs, other than Level 1 inputs. Level 2 inputs would typically include quoted prices in markets that are not active or financial instruments for which all significant inputs are observable, either directly or indirectly.

Level 3 – Prices or valuations that require inputs that are both significant to the measurement and unobservable.

Principles of Consolidation

The consolidated financial statements include the accounts of the Company and its majority-owned subsidiaries and joint ventures. Significant intercompany accounts and transactions have been eliminated. All investments over which we exercise significant influence, but do not control (a 20% to 50% ownership interest), are accounted for using the equity method of accounting. Additionally, we participate in a joint venture with another company, and we have consolidated this joint venture as we have determined that through our participation we have a variable interest and are the primary beneficiary as defined by the Financial Accounting Standards Board (“FASB”) Accounting Standard Codification (“ASC”) Topic 810, “Consolidation”.

For joint ventures that have been accounted for using the consolidation method of accounting, noncontrolling interest represents the allocation of earnings to our joint venture partners who either have a minority-ownership interest in the joint venture or are not at risk for the majority of losses of the joint venture.

The results of operations of companies acquired have been included in the results of operations from the date of the respective acquisition.

Principles of Preparation

The preparation of the consolidated financial statements, in conformity with accounting principles generally accepted in the United States, requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could materially differ from those estimates.

Revenue Recognition

Revenues from long-term construction contracts are recognized on the percentage-of-completion method in accordance with ASC Topic 605-35, “Revenue Recognition-Construction-Type and Production-Type Contracts”. Percentage-of-completion is measured principally by the percentage of costs incurred to date for each contract to the estimated total costs for such contract at completion. Certain of our electrical contracting business units measure percentage-of-completion by the percentage of labor costs incurred to date for each contract to the estimated total labor costs for such contract. Pre-contract costs from our construction projects are generally expensed as incurred. Revenues from the performance of services for maintenance, repair and retrofit work are recognized consistent with the performance of the services, which are generally on a pro-rata basis over the life of the contractual arrangement. Expenses related to all services arrangements are recognized as incurred. Revenues related to the engineering, manufacturing and repairing of shell and tube heat exchangers are recognized when the product is shipped and all other revenue recognition criteria have been met. Costs related to this work are included in inventory until the product is shipped. In the case of customer change orders for uncompleted long-term construction contracts, estimated recoveries are included for work performed in forecasting ultimate profitability on certain contracts. Due to uncertainties inherent in the estimation process, it is possible that completion costs, including those arising from contract penalty provisions and final contract settlements, will be revised in the near-term. Such revisions to costs and income are recognized in the period in which the revisions are determined. Provisions for the entirety of estimated losses on uncompleted contracts are made in the period in which such losses are determined.

Costs and estimated earnings on uncompleted contracts

Costs and estimated earnings in excess of billings on uncompleted contracts arise in the consolidated balance sheets when revenues have been recognized but the amounts cannot be billed under the terms of the contracts. Such amounts are recoverable from customers upon various measures of performance, including achievement of certain milestones, completion of specified units, or completion of a contract. Also included in costs and estimated earnings on uncompleted contracts are amounts we seek or will seek to collect from customers or others for errors or changes in contract specifications or design, contract change orders in dispute or unapproved as to both scope and/or price or other customer-related causes of unanticipated additional contract costs (claims and unapproved change orders). Such amounts are recorded at estimated net realizable value when realization is probable and can be reasonably estimated. No profit is recognized on construction costs incurred in connection with claim amounts. Claims and unapproved change orders made by us involve negotiation and, in certain cases, litigation. In the event litigation costs are incurred by us in connection with claims or unapproved change orders, such litigation costs are expensed as incurred, although we may seek to recover these costs. We believe that we have established legal bases for pursuing recovery of our recorded unapproved change orders and claims, and it is management’s intention to pursue and litigate such claims, if necessary, until a determination or settlement is reached. Unapproved change orders and claims also involve the use of estimates, and it is reasonably possible that revisions to the estimated recoverable amounts of recorded claims and unapproved change orders may be made in the near term. If we do not successfully resolve these matters, a net expense (recorded as a reduction in revenues) may be required, in addition to amounts that may have been previously provided for. We record the profit associated with the settlement of claims upon receipt of final payment. During 2015, we recognized revenues of $12.1 million as a result of the settlement of a claim within our United States mechanical construction and facilities services segment, which represents the recovery of cost on a project in which we incurred significant losses in a prior year. There were no significant settlements or payment of claims in 2014. Claims against us are recognized when a loss is considered probable and amounts are reasonably determinable.

Classification of Contract Amounts

In accordance with industry practice, we classify as current all assets and liabilities relating to the performance of long-term contracts. The term of our contracts ranges from one month to four years and, accordingly, collection or payment of amounts relating to these contracts may extend beyond one year.

Cash and cash equivalents

For purposes of the consolidated financial statements, we consider all highly liquid instruments with original maturities of three months or less to be cash equivalents. We maintain a centralized cash management system whereby our excess cash balances are invested in high quality, short-term money market instruments, which are considered cash equivalents. We have cash balances in certain of our domestic bank accounts that exceed federally insured limits.

Allowance for Doubtful Accounts

Accounts receivable are recorded at the invoiced amount and do not bear interest. The Company maintains an allowance for doubtful accounts. This allowance is based upon the best estimate of the probable losses in existing accounts receivable. The Company determines the allowances based upon individual accounts when information indicates the customers may have an inability to meet their financial obligations, as well as historical collection and write-off experience. These amounts are re-evaluated and adjusted on a regular basis as additional information is received. Actual write-offs are charged against the allowance when collection efforts have been unsuccessful.

Inventories

Inventories are stated at the lower of cost or market. Cost is determined principally using the average cost method.

Property, plant and equipment

Property, plant and equipment is stated at cost. Depreciation, including amortization of assets under capital leases, is recorded principally using the straight-line method over estimated useful lives of 3 to 10 years for machinery and equipment, 3 to 7 years for vehicles, furniture and fixtures and computer hardware/software and 25 years for buildings. Leasehold improvements are amortized over the shorter of the remaining life of the lease term or the expected service life of the improvement.

The carrying values of property, plant and equipment are reviewed for impairment whenever facts and circumstances indicate that the carrying amount may not be fully recoverable. In performing this review for recoverability, property, plant and equipment is assessed for possible impairment by comparing their carrying values to their undiscounted net pre-tax cash flows expected to result from the use of the asset. Impaired assets are written down to their fair values, generally determined based on their estimated future discounted cash flows.

Goodwill and Identifiable Intangible Assets

Goodwill and other identifiable intangible assets with indefinite lives that are not being amortized, such as trade names, are tested at least annually for impairment (which we test each October 1, absent any impairment indicators) and are written down if impaired. Identifiable intangible assets with finite lives are amortized over their useful lives and are reviewed for impairment whenever facts and circumstances indicate that their carrying values may not be fully recoverable. See Note 8 - Goodwill and Identifiable Intangible Assets of the notes to consolidated financial statements for additional information.

Insurance Liabilities

Our insurance liabilities are determined actuarially based on claims filed and an estimate of claims incurred but not yet reported.

Foreign Operations

The financial statements and transactions of our foreign subsidiaries are maintained in their functional currency and translated into U.S. dollars in accordance with ASC Topic 830, “Foreign Currency Matters”. Translation adjustments have been recorded as “Accumulated other comprehensive loss”, a separate component of “Equity”.

Income Taxes

We account for income taxes in accordance with the provisions of ASC Topic 740, “Income Taxes” (“ASC 740”). ASC 740 requires an asset and liability approach which requires the recognition of deferred income tax assets and deferred income tax liabilities for the expected future tax consequences of temporary differences between the carrying amounts and the tax bases of assets and liabilities. Valuation allowances are established when necessary to reduce deferred income tax assets when it is more likely than not that a tax benefit will not be realized.

We account for uncertain tax positions in accordance with the provisions of ASC 740. We recognize accruals of interest related to unrecognized tax benefits as a component of the income tax provision.

Valuation of Share-based Compensation Plans

Valuation of Share-Based Compensation Plans

We have various types of share-based compensation plans and programs, which are administered by our Board of Directors or its Compensation and Personnel Committee. See Note 13 - Share-Based Compensation Plans of the notes to consolidated financial statements for additional information regarding the share-based compensation plans and programs.

We account for share-based payments in accordance with the provisions of ASC Topic 718, “Compensation-Stock Compensation” (“ASC 718”). ASC 718 requires that all share-based payments issued to acquire goods or services, including grants of employee stock options, be recognized in the statement of operations based on their fair values, net of estimated forfeitures. ASC 718 requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Compensation expense related to share-based awards is recognized over the requisite service period, which is generally the vesting period. For shares subject to graded vesting, our policy is to apply the straight-line method in recognizing compensation expense. ASC 718 requires the benefits of tax deductions in excess of recognized compensation expense to be reported as a financing cash inflow, rather than as an operating cash inflow in the Consolidated Statements of Cash Flows. This requirement reduces net operating cash flows and increases net financing cash flows.