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Stockholders' Equity - Schedule of Other Comprehensive Income (Loss), Net of Tax (Details) - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Net actuarial losses attributable to redeemable noncontrolling interest | $ 0 | $ 0 | $ 1,000,000 | $ 1,000,000
Other comprehensive income (loss) before reclassifications | 258,000,000 |  | 578,000,000 |
Reclassified to income statement, net of income tax expense | 1,000,000 |  | 2,000,000 |
Other Comprehensive Income (Loss), Net of Tax | 259,000,000 | (114,000,000) | 580,000,000 | (358,000,000)
Foreign currency translation adjustments arising during period, tax | 0 | 11,000,000 | 0 | (1,000,000)
Reclassified to income statement, tax | 0 | 0 | 0 | 0
Unrealized gains on cash flow hedges arising during period, tax | 0 | 0 | 0 | 0
Net actuarial loss and prior service cost arising during the period, tax | 0 | 0 | 0 | 0
Amortization of actuarial loss and prior service costs, tax | 0 | 1,000,000 | 0 | 2,000,000
Foreign currency translation adjustments and other, tax | 0 | 0 | 0 | 0
Foreign Currency Translation Adjustments, Net of Tax |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Other comprehensive income (loss) before reclassifications | 303,000,000 | (109,000,000) | 685,000,000 | (384,000,000)
Reclassified to income statement, net of income tax expense | 0 | 0 | 0 | 20,000,000
Other Comprehensive Income (Loss), Net of Tax | 303,000,000 | (109,000,000) | 685,000,000 | (364,000,000)
Unrealized Gains (Losses) on Net Investment Hedges, Net of Tax |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Other comprehensive income (loss) before reclassifications | (38,000,000) | 0 | (108,000,000) | 0
Reclassified to income statement, net of income tax expense | 0 | 0 | 0 | 0
Other Comprehensive Income (Loss), Net of Tax | (38,000,000) | 0 | (108,000,000) | 0
Unrealized gains (losses) on net investment hedges arising during period, tax | 25,000,000 | 0 | 69,000,000 | 0
Reclassified to income statement, tax | 0 | 0 | 0 | 0
Unrealized Gains (Losses) on Cash Flow Hedges, Net of Tax |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Other comprehensive income (loss) before reclassifications | (3,000,000) |  | 11,000,000 |
Reclassified to income statement, net of income tax expense | 0 |  | 0 |
Other Comprehensive Income (Loss), Net of Tax | (3,000,000) | (6,000,000) | 11,000,000 | (6,000,000)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service and Net Gain (Loss) |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Other comprehensive income (loss) before reclassifications | 0 | 0 | 0 | 0
Accumulated Defined Benefit Plans Adjustment, Amortization of Actuarial Loss and Prior Service Cost |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Other comprehensive income (loss) before reclassifications | 1,000,000 | 1,000,000 | 2,000,000 | 4,000,000
Accumulated Defined Benefit Plans, Foreign Currency Adjustments |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Other comprehensive income (loss) before reclassifications | (4,000,000) | 0 | (10,000,000) | 8,000,000
Accumulated Defined Benefit Plans Adjustments |  |  |  |
Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |
Other Comprehensive Income (Loss), Net of Tax | $ (3,000,000) | $ 1,000,000 | $ (8,000,000) | $ 12,000,000

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