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Trade Receivables and Unbilled Revenue, Net - Movement in Allowances for Expected Credit Losses (ECL) (Detail) - USD ($) $ in Thousands | 12 Months Ended
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Mar. 31, 2019 | Mar. 31, 2018 | Mar. 31, 2017
Disclosure of financial assets [line items] |  |  |
Balance at the beginning of the year | $ 564 |  |
Balance at the end of the year | 1,182 | $ 564 |
Allowances for expected credit losses [member] |  |  |
Disclosure of financial assets [line items] |  |  |
Balance at the beginning of the year | 564 | 1,713 | $ 4,446
Charged to profit or loss | 1,171 | 2,115 | 777
Write-offs, net of collections | (331) | (1,136) | (2,571)
Reversals | (157) | (2,321) | (664)
Translation adjustment | 9 | 193 | (275)
Balance at the end of the year | 1,182 | 564 | $ 1,713
Allowances for expected credit losses [member] | Previously stated [member] |  |  |
Disclosure of financial assets [line items] |  |  |
Balance at the beginning of the year | 564 |  |
Balance at the end of the year |  | 564 |
Allowances for expected credit losses [member] | Adoption of IFRS 9 [member] |  |  |
Disclosure of financial assets [line items] |  |  |
Balance at the beginning of the year | 74 |  |
Balance at the end of the year |  | 74 |
Allowances for expected credit losses [member] | Adjusted [member] |  |  |
Disclosure of financial assets [line items] |  |  |
Balance at the beginning of the year | $ 490 |  |
Balance at the end of the year |  | $ 490 |

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- Definition The amount of additional allowance for credit losses of financial assets recognised in profit or loss. [Refer: Allowance account for credit losses of financial assets] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Note Expiry date 2021-01-01 -Name IFRS -Number 7 -IssueDate 2018-01-01 -Paragraph 16 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-02&anchor=para_16&doctype=Standard&book=b -URIDate 2018-03-16 + Details
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- Definition The amount of an allowance account used to record impairments to financial assets due to credit losses. [Refer: Financial assets] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Note Expiry date 2021-01-01 -Name IFRS -Number 7 -IssueDate 2018-01-01 -Paragraph 16 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-02&anchor=para_16&doctype=Standard&book=b -URIDate 2018-03-16 + Details
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