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Summary of Significant Accounting Policies - Pension Plan Contributions (Details) $ in Millions | Mar. 31, 2020 USD ($)
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Accounting Policies [Abstract] |
Pension plan employer contributions deferred until 2021 | $ 47

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- Definition Amount of contributions expected to be received by defined benefit plan from employer in next fiscal year following latest fiscal year. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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