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3/31/2010 USD ($) $TwelveMonthsEnded_31Mar2010_Parent_Memberhttp://www.sec.gov/CIK0001356570duration2009-04-01T00:00:002010-03-31T00:00:00falsefalseTotal WNS (Holdings) Ltd shareholders' equityus-gaap_StatementEquityComponentsAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ParentMemberus-gaap_StatementEquityComponentsAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3falsefalseUSDtruefalse{us-gaap_StatementEquityComponentsAxis} : Total WNS (Holdings) Ltd shareholders' equity 4/1/2008 - 3/31/2009 USD ($) $TwelveMonthsEnded_31Mar2009_Parent_Memberhttp://www.sec.gov/CIK0001356570duration2008-04-01T00:00:002009-03-31T00:00:00falsefalseTotal WNS (Holdings) Ltd shareholders' equityus-gaap_StatementEquityComponentsAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_ParentMemberus-gaap_StatementEquityComponentsAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalseTotal WNS (Holdings) Ltd shareholders' equity2false0us-gaap_OtherComprehensiveIncomeReclassificationAdjustmentOnDerivativesIncludedInNetIncomeNetOfTaxus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse45050004505falsetruefalsefalsefalse2truefalsefalse35840003584falsetruefalsefalsefalse3truefalsefalse26800002680falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNet of tax effect of the reclassification adjustment for accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of cash flow hedges included in accumulated comprehensive income that was realized in net income during the period.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 18, 19 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(3) Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 24 -Subparagraph b Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 31, 46 falsefalseCash flow hedges, net of reclassification adjustment3false0us-gaap_OtherComprehensiveIncomeMinimumPensionLiabilityNetAdjustmentTaxus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse3300033falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe tax effect of the amount of the change in the additional minimum pension liability not yet recognized pursuant to FAS 87 as a net periodic pension cost. 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Eliminated upon adoption of FAS 158.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(3) Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 25 falsefalsePension Adjustment, net of tax4false0us-gaap_OtherComprehensiveIncomeDerivativesQualifyingAsHedgesTaxEffectPeriodIncreaseDecreaseus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse3600036falsefalsefalsefalsefalse2truefalsefalse9200092falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal tax effect of the change in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges after taxes. 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