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Goodwill - Additional Information (Detail) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Mar. 31, 2019 | Mar. 31, 2018 | Mar. 31, 2017 | Apr. 01, 2018
Disclosure of reconciliation of changes in goodwill [line items] |  |  |  |
Estimated cash flows period | Five years |  |  |
Impairment charge | $ 0 | $ 0 | $ (21,673) |
Goodwill | $ 130,811 | 135,186 |  | $ 135,186
WNS Auto Claims BPM [member] |  |  |  |
Disclosure of reconciliation of changes in goodwill [line items] |  |  |  |
Impairment charge |  |  | $ 21,673 |
Discount rate | 15.50% |  | 13.00% |
Growth rate | 2.00% |  |  |
Recoverable amount of cash generating units |  |  | $ 37,836 |
Goodwill | $ 4,315 | $ 4,633 | 4,130 |
Disposal cost |  |  | $ 656 |
WNS Auto Claims BPM [member] | Annual Growth Rate [member] |  |  |  |
Disclosure of reconciliation of changes in goodwill [line items] |  |  |  |
Growth rate |  |  | 2.50% |
WNS Auto Claims BPM [member] | Perpetual Growth Rate [member] |  |  |  |
Disclosure of reconciliation of changes in goodwill [line items] |  |  |  |
Growth rate |  |  | 2.00% |

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- Definition The explanation of the period over which management has projected cash flows based on financial budgets/forecasts approved by management including, when a period greater than five years is used for a cash-generating unit (group of units), an explanation of why that longer period is justified. [Refer: Cash-generating units [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 134 -Subparagraph d -Clause iii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_d_iii&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 134 -Subparagraph e -Clause iii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_e_iii&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition The amount of impairment loss recognised in profit or loss for goodwill. [Refer: Impairment loss recognised in profit or loss; Goodwill] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 3 -IssueDate 2018-01-01 -Paragraph B67 -Subparagraph d -Clause v -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=3&date=2018-03-01&anchor=para_B67_d_v&doctype=Appendix&seq=2 -URIDate 2018-03-16 + Details
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