v3.7.0.1

Segment Information - Depreciation and Amortization Expense Included in Direct Expenses and Unallocated Selling, General, and Administrative Costs (Detail) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2017 | Jun. 30, 2016 | Jun. 30, 2017 | Jun. 30, 2016
Reportable Operating Segments [Member] |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Depreciation and Amortization Expenses | $ 15,191 | $ 15,313 | $ 30,676 | $ 29,614
Reportable Operating Segments [Member] | Oil and Gas [Member] |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Depreciation and Amortization Expenses | 9,824 | 10,024 | 19,686 | 19,942
Reportable Operating Segments [Member] | Air Medical [Member] |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Depreciation and Amortization Expenses | 5,219 | 5,132 | 10,696 | 9,387
Reportable Operating Segments [Member] | Technical Services [Member] |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Depreciation and Amortization Expenses | 148 | 157 | 294 | 285
Corporate [Member] |  |  |  |
Segment Reporting, Asset Reconciling Item [Line Items] |  |  |  |
Depreciation and Amortization Expenses | $ 622 | $ 2,476 | $ 3,335 | $ 5,147

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- Definition The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585 + Details
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- 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
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