<?xml version='1.0' encoding='UTF-8'?>
<FilingSummary>
  <Version>3.7.0.1</Version>
  <ProcessingTime/>
  <ReportFormat>html</ReportFormat>
  <ContextCount>163</ContextCount>
  <ElementCount>194</ElementCount>
  <EntityCount>1</EntityCount>
  <FootnotesReported>false</FootnotesReported>
  <SegmentCount>52</SegmentCount>
  <ScenarioCount>0</ScenarioCount>
  <TuplesReported>false</TuplesReported>
  <UnitCount>9</UnitCount>
  <MyReports>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R1.htm</HtmlFileName>
      <LongName>0001000 - Document - Document and Entity Information</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/DocumentAndEntityInformation</Role>
      <ShortName>Document and Entity Information</ShortName>
      <MenuCategory>Cover</MenuCategory>
      <Position>1</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R2.htm</HtmlFileName>
      <LongName>1001000 - Statement - Consolidated Balance Sheets</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/ConsolidatedBalanceSheets</Role>
      <ShortName>Consolidated Balance Sheets</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>2</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R3.htm</HtmlFileName>
      <LongName>1001501 - Statement - Consolidated Balance Sheets (Parenthetical)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/ConsolidatedBalanceSheetsParenthetical</Role>
      <ShortName>Consolidated Balance Sheets (Parenthetical)</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>3</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R4.htm</HtmlFileName>
      <LongName>1002000 - Statement - Consolidated Statements of Earnings and Comprehensive (Loss) Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/ConsolidatedStatementsOfEarningsAndComprehensiveLossIncome</Role>
      <ShortName>Consolidated Statements of Earnings and Comprehensive (Loss) Income</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>4</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R5.htm</HtmlFileName>
      <LongName>1003000 - Statement - Consolidated Statements of Cash Flows</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/ConsolidatedStatementsOfCashFlows</Role>
      <ShortName>Consolidated Statements of Cash Flows</ShortName>
      <MenuCategory>Statements</MenuCategory>
      <Position>5</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R6.htm</HtmlFileName>
      <LongName>2101100 - Disclosure - Basis of Presentation and Significant Accounting Policies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/BasisOfPresentationAndSignificantAccountingPolicies</Role>
      <ShortName>Basis of Presentation and Significant Accounting Policies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>6</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R7.htm</HtmlFileName>
      <LongName>2102100 - Disclosure - Recent Accounting Pronouncements</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/RecentAccountingPronouncements</Role>
      <ShortName>Recent Accounting Pronouncements</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>7</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R8.htm</HtmlFileName>
      <LongName>2106100 - Disclosure - Inventory</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/Inventory</Role>
      <ShortName>Inventory</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>8</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R9.htm</HtmlFileName>
      <LongName>2107100 - Disclosure - Goodwill</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/Goodwill</Role>
      <ShortName>Goodwill</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>9</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R10.htm</HtmlFileName>
      <LongName>2108100 - Disclosure - Fair Value of Financial Instruments</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/FairValueOfFinancialInstruments</Role>
      <ShortName>Fair Value of Financial Instruments</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>10</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R11.htm</HtmlFileName>
      <LongName>2109100 - Disclosure - Long-Term Debt</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/LongTermDebt</Role>
      <ShortName>Long-Term Debt</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>11</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R12.htm</HtmlFileName>
      <LongName>2110100 - Disclosure - Comprehensive (Loss) Income</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/ComprehensiveLossIncome</Role>
      <ShortName>Comprehensive (Loss) Income</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>12</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R13.htm</HtmlFileName>
      <LongName>2111100 - Disclosure - Net Income Per Share</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/NetIncomePerShare</Role>
      <ShortName>Net Income Per Share</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>13</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R14.htm</HtmlFileName>
      <LongName>2112100 - Disclosure - Segment Reporting</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/SegmentReporting</Role>
      <ShortName>Segment Reporting</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>14</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R15.htm</HtmlFileName>
      <LongName>2113100 - Disclosure - Income Taxes</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/IncomeTaxes</Role>
      <ShortName>Income Taxes</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>15</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R16.htm</HtmlFileName>
      <LongName>2114100 - Disclosure - Commitments and Contingencies</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/CommitmentsAndContingencies</Role>
      <ShortName>Commitments and Contingencies</ShortName>
      <MenuCategory>Notes</MenuCategory>
      <Position>16</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R17.htm</HtmlFileName>
      <LongName>2201201 - Disclosure - Basis of Presentation and Significant Accounting Policies (Policies)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/BasisOfPresentationAndSignificantAccountingPoliciesPolicies</Role>
      <ShortName>Basis of Presentation and Significant Accounting Policies (Policies)</ShortName>
      <MenuCategory>Policies</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/BasisOfPresentationAndSignificantAccountingPolicies</ParentRole>
      <Position>17</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R18.htm</HtmlFileName>
      <LongName>2307301 - Disclosure - Goodwill (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/GoodwillTables</Role>
      <ShortName>Goodwill (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/Goodwill</ParentRole>
      <Position>18</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R19.htm</HtmlFileName>
      <LongName>2308301 - Disclosure - Fair Value of Financial Instruments (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/FairValueOfFinancialInstrumentsTables</Role>
      <ShortName>Fair Value of Financial Instruments (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/FairValueOfFinancialInstruments</ParentRole>
      <Position>19</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R20.htm</HtmlFileName>
      <LongName>2309301 - Disclosure - Long-Term Debt (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/LongTermDebtTables</Role>
      <ShortName>Long-Term Debt (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/LongTermDebt</ParentRole>
      <Position>20</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R21.htm</HtmlFileName>
      <LongName>2310301 - Disclosure - Comprehensive (Loss) Income (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/ComprehensiveLossIncomeTables</Role>
      <ShortName>Comprehensive (Loss) Income (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/ComprehensiveLossIncome</ParentRole>
      <Position>21</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R22.htm</HtmlFileName>
      <LongName>2311301 - Disclosure - Net Income Per Share (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/NetIncomePerShareTables</Role>
      <ShortName>Net Income Per Share (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/NetIncomePerShare</ParentRole>
      <Position>22</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R23.htm</HtmlFileName>
      <LongName>2312301 - Disclosure - Segment Reporting (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/SegmentReportingTables</Role>
      <ShortName>Segment Reporting (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/SegmentReporting</ParentRole>
      <Position>23</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R24.htm</HtmlFileName>
      <LongName>2313301 - Disclosure - Income Taxes (Tables)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/IncomeTaxesTables</Role>
      <ShortName>Income Taxes (Tables)</ShortName>
      <MenuCategory>Tables</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/IncomeTaxes</ParentRole>
      <Position>24</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R25.htm</HtmlFileName>
      <LongName>2402401 - Disclosure - Recent Accounting Pronouncements (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/RecentAccountingPronouncementsDetails</Role>
      <ShortName>Recent Accounting Pronouncements (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/RecentAccountingPronouncements</ParentRole>
      <Position>25</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R26.htm</HtmlFileName>
      <LongName>2406401 - Disclosure - Inventory (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/InventoryDetails</Role>
      <ShortName>Inventory (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/Inventory</ParentRole>
      <Position>26</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R27.htm</HtmlFileName>
      <LongName>2407402 - Disclosure - Goodwill - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/GoodwillAdditionalInformationDetails</Role>
      <ShortName>Goodwill - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>27</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R28.htm</HtmlFileName>
      <LongName>2407403 - Disclosure - Goodwill - Schedule of Goodwill (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/GoodwillScheduleOfGoodwillDetails</Role>
      <ShortName>Goodwill - Schedule of Goodwill (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>28</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R29.htm</HtmlFileName>
      <LongName>2408402 - Disclosure - Fair Value of Financial Instruments - Cash Flow Hedges of Interest Rate Risk (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/FairValueOfFinancialInstrumentsCashFlowHedgesOfInterestRateRiskDetails</Role>
      <ShortName>Fair Value of Financial Instruments - Cash Flow Hedges of Interest Rate Risk (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>29</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R30.htm</HtmlFileName>
      <LongName>2408403 - Disclosure - Fair Value of Financial Instruments - Non-Designated Derivatives (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/FairValueOfFinancialInstrumentsNonDesignatedDerivativesDetails</Role>
      <ShortName>Fair Value of Financial Instruments - Non-Designated Derivatives (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>30</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R31.htm</HtmlFileName>
      <LongName>2408404 - Disclosure - Fair Value of Financial Instruments - Location and Fair Value Amounts of Financial Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/FairValueOfFinancialInstrumentsLocationAndFairValueAmountsOfFinancialInstrumentsDetails</Role>
      <ShortName>Fair Value of Financial Instruments - Location and Fair Value Amounts of Financial Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>31</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R32.htm</HtmlFileName>
      <LongName>2408405 - Disclosure - Fair Value of Financial Instruments - Losses of Cash Flow Hedge Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/FairValueOfFinancialInstrumentsLossesOfCashFlowHedgeInstrumentsDetails</Role>
      <ShortName>Fair Value of Financial Instruments - Losses of Cash Flow Hedge Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>32</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R33.htm</HtmlFileName>
      <LongName>2408406 - Disclosure - Fair Value of Financial Instruments - Effective Portion of Gain Recognized In OCI (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/FairValueOfFinancialInstrumentsEffectivePortionOfGainRecognizedInOciDetails</Role>
      <ShortName>Fair Value of Financial Instruments - Effective Portion of Gain Recognized In OCI (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>33</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R34.htm</HtmlFileName>
      <LongName>2408407 - Disclosure - Fair Value of Financial Instruments - Changes in AOCI (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/FairValueOfFinancialInstrumentsChangesInAociDetails</Role>
      <ShortName>Fair Value of Financial Instruments - Changes in AOCI (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>34</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R35.htm</HtmlFileName>
      <LongName>2408408 - Disclosure - Fair Value of Financial Instruments - Pretax Effect of Derivative Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/FairValueOfFinancialInstrumentsPretaxEffectOfDerivativeInstrumentsDetails</Role>
      <ShortName>Fair Value of Financial Instruments - Pretax Effect of Derivative Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>35</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R36.htm</HtmlFileName>
      <LongName>2408409 - Disclosure - Fair Value of Financial Instruments - Other Financial Instruments (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/FairValueOfFinancialInstrumentsOtherFinancialInstrumentsDetails</Role>
      <ShortName>Fair Value of Financial Instruments - Other Financial Instruments (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>36</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R37.htm</HtmlFileName>
      <LongName>2408410 - Disclosure - Fair Value of Financial Instruments - Fair Value Measurement (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/FairValueOfFinancialInstrumentsFairValueMeasurementDetails</Role>
      <ShortName>Fair Value of Financial Instruments - Fair Value Measurement (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>37</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R38.htm</HtmlFileName>
      <LongName>2409402 - Disclosure - Long-Term Debt Long-Term Debt - Additional Information (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/LongTermDebtLongTermDebtAdditionalInformationDetails</Role>
      <ShortName>Long-Term Debt Long-Term Debt - Additional Information (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>38</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R39.htm</HtmlFileName>
      <LongName>2409403 - Disclosure - Long-Term Debt - Schedule of Long-term Debt (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/LongTermDebtScheduleOfLongTermDebtDetails</Role>
      <ShortName>Long-Term Debt - Schedule of Long-term Debt (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>39</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R40.htm</HtmlFileName>
      <LongName>2409404 - Disclosure - Long-Term Debt - Deferred Financing Costs (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/LongTermDebtDeferredFinancingCostsDetails</Role>
      <ShortName>Long-Term Debt - Deferred Financing Costs (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <Position>40</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R41.htm</HtmlFileName>
      <LongName>2410402 - Disclosure - Comprehensive (Loss) Income (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/ComprehensiveLossIncomeDetails</Role>
      <ShortName>Comprehensive (Loss) Income (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/ComprehensiveLossIncomeTables</ParentRole>
      <Position>41</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R42.htm</HtmlFileName>
      <LongName>2411402 - Disclosure - Net Income Per Share (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/NetIncomePerShareDetails</Role>
      <ShortName>Net Income Per Share (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/NetIncomePerShareTables</ParentRole>
      <Position>42</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R43.htm</HtmlFileName>
      <LongName>2412402 - Disclosure - Segment Reporting (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/SegmentReportingDetails</Role>
      <ShortName>Segment Reporting (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/SegmentReportingTables</ParentRole>
      <Position>43</Position>
    </Report>
    <Report instance="wair-20170630.xml">
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <HtmlFileName>R44.htm</HtmlFileName>
      <LongName>2413402 - Disclosure - Income Taxes (Details)</LongName>
      <ReportType>Sheet</ReportType>
      <Role>http://www.wescoair.com/role/IncomeTaxesDetails</Role>
      <ShortName>Income Taxes (Details)</ShortName>
      <MenuCategory>Details</MenuCategory>
      <ParentRole>http://www.wescoair.com/role/IncomeTaxesTables</ParentRole>
      <Position>44</Position>
    </Report>
    <Report>
      <IsDefault>false</IsDefault>
      <HasEmbeddedReports>false</HasEmbeddedReports>
      <LongName>All Reports</LongName>
      <ReportType>Book</ReportType>
      <ShortName>All Reports</ShortName>
    </Report>
  </MyReports>
  <InputFiles>
    <File>wair-20170630.xml</File>
    <File>wair-20170630.xsd</File>
    <File>wair-20170630_cal.xml</File>
    <File>wair-20170630_def.xml</File>
    <File>wair-20170630_lab.xml</File>
    <File>wair-20170630_pre.xml</File>
  </InputFiles>
  <SupplementalFiles/>
  <BaseTaxonomies/>
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
