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Hedging Activities - Narrative (Details) £ in Millions, $ in Millions | 3 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Jun. 30, 2021 USD ($) | Jun. 30, 2020 USD ($) | Jun. 30, 2021 EUR (€) | Jun. 30, 2021 CAD ($) | Mar. 31, 2021 USD ($) | Mar. 31, 2021 EUR (€) | Mar. 31, 2021 CAD ($) | Jun. 30, 2020 EUR (€) | Apr. 27, 2020 USD ($) | Apr. 27, 2020 EUR (€) | Sep. 30, 2019 GBP (£)
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |
Gains (losses) from cash flow hedges recorded within other comprehensive income | $ 0 | $ (5,000,000) |  |  |  |  |  |  |  |  |
Derivatives designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |
Gain (loss) from net investment hedges recorded within other comprehensive income | (22,000,000) | (34,000,000) |  |  |  |  |  |  |  |  |
Forward contracts to hedge Euro against British Pound cash flows | Derivatives not designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |
Notional values of financial instruments | 54,000,000 |  |  |  | $ 39,000,000 |  |  |  |  |  |
Net Investment Hedging | Derivatives designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |
Derivatives used in net investment hedge, gains (losses) gross | (5,000,000) | (51,000,000) |  |  |  |  |  |  |  |  |
Net Investment Hedging | November 2018 cross currency swaps | Derivatives designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |
Notional values of financial instruments |  |  |  | $ 500 |  |  | $ 500 |  |  |  |
Cash Flow Hedging | Derivatives designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |
Gains (losses) from cash flow hedges recorded within other comprehensive income | 0 | $ (5,000,000) |  |  |  |  |  |  |  |  |
Cash Flow Hedging | Cross currency swap | Derivatives designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |
Notional values of financial instruments | $ 2,600,000,000 |  |  |  | $ 2,600,000,000 |  |  |  |  |  |
Cash Flow Hedging | Forward starting interest rate swaps | Derivatives designated for hedge accounting |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |
Notional values of financial instruments |  |  |  |  |  |  |  |  | $ 500,000,000 | € 600,000,000 |
Euro Denominated Notes | Term Loan |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |
Long-term debt outstanding | € |  |  |  |  |  |  |  | € 1,700,000,000 |  |  |
Euro Denominated Notes | Term Loan | Net Investment Hedging |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |
Long-term debt outstanding | € |  |  | € 1,700,000,000 |  |  | € 1,700,000,000 |  |  |  |  |
British Pound Sterling Denominated Notes | Term Loan |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |
Long-term debt outstanding | £ |  |  |  |  |  |  |  |  |  |  | £ 450
2025 Notes | Term Loan |  |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument term | 5 years |  |  |  |  |  |  |  |  |  |

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