Segment Information (Net Revenue By Geographic Area) (Details) - USD ($) $ in Millions	3 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Revenue from External Customer [Line Items]
Net revenue	$ 1,459	$ 1,209
North America
Revenue from External Customer [Line Items]
Net revenue	627	490
International
Revenue from External Customer [Line Items]
Net revenue	$ 832	$ 719

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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+ Details