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Financial Derivatives and Hedging Activities - Outstanding Derivatives Used to Hedge Foreign Exchange Risks (Detail) | Jun. 30, 2020 USD ($) | Jun. 30, 2020 EUR (€) | Jun. 30, 2020 PHP (₱) | Jun. 30, 2020 CAD ($) | Jun. 30, 2020 GBP (£) | Dec. 31, 2019 USD ($) | Dec. 31, 2019 EUR (€) | Dec. 31, 2019 PHP (₱) | Dec. 31, 2019 CAD ($) | Dec. 31, 2019 GBP (£)
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Cash Flow Hedges [Member] | Euro / British Pound [Member] | Designated as Hedging [Member] | Sell Notional [Member] |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative notional amount | € |  | € 18,966,000 |  |  |  |  | € 17,702,000 |  |  |
Cash Flow Hedges [Member] | U.S Dollar / Euro [Member] | Designated as Hedging [Member] | Sell Notional [Member] |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative notional amount | $ 8,322,000 |  |  |  |  | $ 5,347,000 |  |  |  |
Cash Flow Hedges [Member] | U.S. Dollar / Canadian Dollar [Member] | Designated as Hedging [Member] | Sell Notional [Member] |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative notional amount | 1,153,000 |  |  |  |  | 1,523,000 |  |  |  |
Cash Flow Hedges [Member] | U.S. Dollar / Canadian Dollar [Member] | Designated as Hedging [Member] | Buy Notional [Member] |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative notional amount |  |  |  | $ 34,111,000 |  |  |  |  | $ 34,094,000 |
Cash Flow Hedges [Member] | Euro / Philippine Peso [Member] | Designated as Hedging [Member] | Buy Notional [Member] |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative notional amount | ₱ |  |  | ₱ 976,397,000 |  |  |  |  | ₱ 1,039,432,000 |  |
Cash Flow Hedges [Member] | British Pound / Philippine Peso [Member] | Designated as Hedging [Member] | Buy Notional [Member] |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative notional amount | ₱ |  |  | ₱ 1,111,995,000 |  |  |  |  | ₱ 1,077,871,000 |  |
Cash Flow Hedges [Member] | Euro / U.S. Dollar [Member] | Designated as Hedging [Member] | Buy Notional [Member] |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative notional amount | 73,257,000 |  |  |  |  | 82,317,000 |  |  |  |
Cash Flow Hedges [Member] | Canadian Dollar / U.S. Dollar [Member] | Designated as Hedging [Member] | Buy Notional [Member] |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative notional amount | 1,153,000 |  |  |  |  | 1,523,000 |  |  |  |
Foreign Currency Hedges [Member] | Euro / U.S. Dollar [Member] | Not Designated as Hedging [Member] | Buy Notional [Member] |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative notional amount | 3,500,000 |  |  |  |  | 8,000,000 |  |  |  |
Foreign Currency Hedges [Member] | U.S. Dollar / British Pound [Member] | Not Designated as Hedging [Member] | Sell Notional [Member] |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative notional amount | $ 26,000,000 |  |  |  |  | $ 25,500,000 |  |  |  |
Foreign Currency Hedges [Member] | British Pound / Euro [Member] | Not Designated as Hedging [Member] | Sell Notional [Member] |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative notional amount | £ |  |  |  |  | £ 3,000,000 |  |  |  |  | £ 3,000,000
Foreign Currency Hedges [Member] | British Pound / Euro [Member] | Not Designated as Hedging [Member] | Buy Notional [Member] |  |  |  |  |  |  |  |  |  |
Derivative Instruments And Hedging Activities Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative notional amount | € |  | € 5,000,000 |  |  |  |  | € 7,000,000 |  |  |

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