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Debt and Financing Activities - Long Term Debt (Details) |  | 9 Months Ended |
--- | --- | --- | ---
Nov. 30, 2018 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 EUR (€) | Dec. 31, 2017 USD ($) | Mar. 31, 2018 USD ($)
Debt Instrument [Line Items] |  |  |  |  |
Long-term debt outstanding |  | $ 8,736,000,000 |  |  | $ 7,880,000,000
Proceeds from issuances of notes |  | 1,099,000,000 |  | $ 0 |
Term Loan | Euro Dond Due April 2017 |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Bond repaid | € |  |  | € 500,000,000 |  |
Notes payable | Notes Due November 30, 2020 and Notes Due May 30, 2029 |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Proceeds from issuances of notes | $ 1,100,000,000 |  |  |  |
Repurchase price of principal outstanding (percent) | 101.00% |  |  |  |
Notes payable | Notes Due November 30, 2020 |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Stated rate of notes issued (percent) | 3.65% |  |  |  |
Principal amount of notes issued | $ 700,000,000 |  |  |  |
Notes payable | Notes Due May 30, 2029 |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Stated rate of notes issued (percent) | 4.75% |  |  |  |
Principal amount of notes issued | $ 400,000,000 |  |  |  |
Current Portion of Long-term Debt |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Long-term debt outstanding |  | $ 1,120,000,000 |  |  | $ 1,129,000,000

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- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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