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Financial Instruments - Notional Values of Outstanding Foreign Exchange Forward Contracts, Foreign Exchange Option Contracts and Interest Rate Swap Contracts (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 31, 2017
Forward contracts (sell) [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	$ 449,371	$ 429,868
Forward contracts (sell) [member] | US Dollars [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	242,418	241,673
Forward contracts (sell) [member] | United Kingdom Pound Sterling [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	132,591	126,441
Forward contracts (sell) [member] | Euro [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	23,883	14,769
Forward contracts (sell) [member] | Australian Dollars [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	48,147	43,474
Forward contracts (sell) [member] | Others Currencies [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	2,332	3,511
Option contracts (sell) [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	275,268	214,468
Option contracts (sell) [member] | US Dollars [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	107,629	84,490
Option contracts (sell) [member] | United Kingdom Pound Sterling [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	116,401	94,094
Option contracts (sell) [member] | Euro [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	21,483	14,494
Option contracts (sell) [member] | Australian Dollars [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	28,828	19,412
Option contracts (sell) [member] | Others Currencies [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	927	1,978
Interest rate swap contracts [member] | US Dollars [member]
Disclosure of detailed information about financial instruments [line items]
Derivative, notional amount	$ 89,900	$ 118,000

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- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

+ References

No definition available.

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- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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