Debt - Schedule of Debt (Details) | 3 Months Ended | | |
Jun. 30, 2019EUR (€) | Jun. 30, 2019USD ($) | Jun. 30, 2019GBP (£) | Mar. 31, 2019USD ($) |
Short-term debt and current maturities of long-term debt | | | | |
Euro-denominated commercial paper | | $ 704,000,000 | | $ 694,000,000 |
Current maturities of long-term debt | | 329,000,000 | | 766,000,000 |
Current maturities of finance lease liabilities | | 478,000,000 | | |
Current maturities of finance lease liabilities | | | | 482,000,000 |
Short-term debt and current maturities of long-term debt | | 1,511,000,000 | | 1,942,000,000 |
Long-term debt, net of current maturities | | | | |
Long-term debt | | 8,700,000,000 | | 6,718,000,000 |
Finance lease liabilities | | 1,216,000,000 | | |
Finance lease liabilities | | | | 1,127,000,000 |
Less: current maturities | | 807,000,000 | | 1,248,000,000 |
Long-term debt, net of current maturities | | 7,893,000,000 | | 5,470,000,000 |
Term loan | Term Loan Payable, AUD, Due 2021 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | 561,000,000 | | 567,000,000 |
Term loan | Term Loan Payable, GBP, Due 2022 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | 571,000,000 | | 583,000,000 |
Term loan | Term Loan Payable, EUR, Due 2022 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 852,000,000 | | 0 |
Debt Information [Abstract] | | | | |
Effective interest rate | 0.65% | 0.65% | 0.65% | |
Term loan | Term Loan Payable, EUR, Due 2023 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 852,000,000 | | 0 |
Debt Information [Abstract] | | | | |
Effective interest rate | 0.80% | 0.80% | 0.80% | |
Term loan | Term Loan Payable, USD, Due 2025 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 498,000,000 | | 0 |
Debt Information [Abstract] | | | | |
Effective interest rate | 3.67% | 3.67% | 3.67% | |
Senior notes | Senior notes due 2020 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 0 | | 502,000,000 |
Debt Information [Abstract] | | | | |
Effective interest rate | 2.88% | 2.88% | 2.88% | |
Face amount | | $ 500,000,000 | | |
Senior notes | Senior notes due 2021 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | 498,000,000 | | 498,000,000 |
Debt Information [Abstract] | | | | |
Face amount | | 500,000,000 | | |
Senior notes | Senior notes due 2023 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 277,000,000 | | 277,000,000 |
Debt Information [Abstract] | | | | |
Effective interest rate | 4.45% | 4.45% | 4.45% | |
Face amount | | $ 274,000,000 | | |
Senior notes | Senior notes due 2023 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 172,000,000 | | 172,000,000 |
Debt Information [Abstract] | | | | |
Effective interest rate | 4.45% | 4.45% | 4.45% | |
Face amount | | $ 171,000,000 | | |
Senior notes | Senior notes due 2025 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 506,000,000 | | 506,000,000 |
Debt Information [Abstract] | | | | |
Effective interest rate | 4.25% | 4.25% | 4.25% | |
Face amount | | $ 500,000,000 | | |
Senior notes | Senior notes due 2025 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 315,000,000 | | 322,000,000 |
Debt Information [Abstract] | | | | |
Effective interest rate | 2.75% | 2.75% | 2.75% | |
Face amount | € 250,000,000 | | £ 250,000,000 | |
Senior notes | Senior notes due 2026 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 735,000,000 | | 725,000,000 |
Debt Information [Abstract] | | | | |
Effective interest rate | 1.75% | 1.75% | 1.75% | |
Face amount | € | € 650,000,000 | | | |
Senior notes | Senior notes due 2028 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 508,000,000 | | 508,000,000 |
Debt Information [Abstract] | | | | |
Effective interest rate | 4.75% | 4.75% | 4.75% | |
Face amount | | $ 500,000,000 | | |
Senior notes | Senior notes due 2030 | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 273,000,000 | | 273,000,000 |
Debt Information [Abstract] | | | | |
Effective interest rate | 7.45% | 7.45% | 7.45% | |
Face amount | | $ 234,000,000 | | |
Secured debt | Lease credit facility | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | 21,000,000 | | 25,000,000 |
Borrowings for assets acquired under long-term financing | | | | |
Long-term debt, net of current maturities | | | | |
Borrowings for assets acquired under long-term financing | | 707,000,000 | | 462,000,000 |
Mandatorily redeemable preferred stock outstanding | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 62,000,000 | | 62,000,000 |
Debt Information [Abstract] | | | | |
Effective interest rate | 6.00% | 6.00% | 6.00% | |
Other borrowings | | | | |
Long-term debt, net of current maturities | | | | |
Long-term debt | | $ 76,000,000 | | $ 109,000,000 |
Minimum | Term loan | Term Loan Payable, AUD, Due 2021 | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 2.29% | 2.29% | 2.29% | |
Minimum | Term loan | Term Loan Payable, GBP, Due 2022 | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 1.60% | 1.60% | 1.60% | |
Minimum | Senior notes | Senior notes due 2021 | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 3.47% | 3.47% | 3.47% | |
Minimum | Secured debt | Lease credit facility | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 3.44% | 3.44% | 3.44% | |
Minimum | Finance lease liabilities | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 1.10% | 1.10% | 1.10% | |
Minimum | Borrowings for assets acquired under long-term financing | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 1.76% | 1.76% | 1.76% | |
Minimum | Other borrowings | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 0.50% | 0.50% | 0.50% | |
Maximum | Term loan | Term Loan Payable, AUD, Due 2021 | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 2.66% | 2.66% | 2.66% | |
Maximum | Term loan | Term Loan Payable, GBP, Due 2022 | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 1.62% | 1.62% | 1.62% | |
Maximum | Senior notes | Senior notes due 2021 | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 3.69% | 3.69% | 3.69% | |
Maximum | Secured debt | Lease credit facility | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 3.50% | 3.50% | 3.50% | |
Maximum | Finance lease liabilities | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 11.70% | 11.70% | 11.70% | |
Maximum | Borrowings for assets acquired under long-term financing | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 4.50% | 4.50% | 4.50% | |
Maximum | Other borrowings | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 7.40% | 7.40% | 7.40% | |
EURIBOR | Minimum | Term loan | Term Loan Payable, EUR, Due 2022 | | | | |
Debt Information [Abstract] | | | | |
Basis spread on variable rate | 0.40% | | | |
EURIBOR | Minimum | Term loan | Term Loan Payable, EUR, Due 2023 | | | | |
Debt Information [Abstract] | | | | |
Basis spread on variable rate | 0.55% | | | |
EURIBOR | Minimum | Term loan | Term Loan Payable, USD, Due 2025 | | | | |
Debt Information [Abstract] | | | | |
Basis spread on variable rate | 1.00% | | | |
EURIBOR | Maximum | Term loan | Term Loan Payable, EUR, Due 2022 | | | | |
Debt Information [Abstract] | | | | |
Basis spread on variable rate | 0.90% | | | |
EURIBOR | Maximum | Term loan | Term Loan Payable, EUR, Due 2023 | | | | |
Debt Information [Abstract] | | | | |
Basis spread on variable rate | 1.05% | | | |
EURIBOR | Maximum | Term loan | Term Loan Payable, USD, Due 2025 | | | | |
Debt Information [Abstract] | | | | |
Basis spread on variable rate | 1.50% | | | |
Bank Bill Swap Rate | Minimum | Term loan | Term Loan Payable, AUD, Due 2021 | | | | |
Debt Information [Abstract] | | | | |
Basis spread on variable rate | 0.60% | | | |
Bank Bill Swap Rate | Maximum | Term loan | Term Loan Payable, AUD, Due 2021 | | | | |
Debt Information [Abstract] | | | | |
Basis spread on variable rate | 0.95% | | | |
Three-month LIBOR | Term loan | Term Loan Payable, GBP, Due 2022 | | | | |
Debt Information [Abstract] | | | | |
Basis spread on variable rate | 0.80% | | | |
Three-month LIBOR | Senior notes | Senior notes due 2021 | | | | |
Debt Information [Abstract] | | | | |
Basis spread on variable rate | 0.95% | | | |
Base Rate | Minimum | Term loan | Term Loan Payable, USD, Due 2025 | | | | |
Debt Information [Abstract] | | | | |
Basis spread on variable rate | 0.00% | | | |
Base Rate | Maximum | Term loan | Term Loan Payable, USD, Due 2025 | | | | |
Debt Information [Abstract] | | | | |
Basis spread on variable rate | 0.50% | | | |
Commercial paper | | | | |
Debt Information [Abstract] | | | | |
Maximum borrowing capacity | € | € 1,000,000,000 | | | |
Commercial paper | Minimum | | | | |
Debt Information [Abstract] | | | | |
Weighted average interest rate, short- term debt | (0.10%) | (0.10%) | (0.10%) | |
Commercial paper | Maximum | | | | |
Debt Information [Abstract] | | | | |
Weighted average interest rate, short- term debt | 2.76% | 2.76% | 2.76% | |
Finance Lease Liabilities | Minimum | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 1.10% | 1.10% | 1.10% | |
Finance Lease Liabilities | Maximum | | | | |
Debt Information [Abstract] | | | | |
Effective interest rate | 11.70% | 11.70% | 11.70% | |