Fair Value Measurements (Schedule of the Carrying Value of Assets Measured at Fair Value on a Recurring Basis) (Details) - Recurring - USD ($) $ in Millions	Dec. 29, 2017	Mar. 31, 2017
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	$ 2,532	$ 4,256
Fair Value | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	712	1,183
Fair Value | Non-negotiable certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	381	15
Fair Value | Level 1 (Quoted prices in active markets for identical assets):
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	878	2,635
Fair Value | Level 1 (Quoted prices in active markets for identical assets): | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	814	2,532
Fair Value | Level 1 (Quoted prices in active markets for identical assets): | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	64	94
Fair Value | Level 1 (Quoted prices in active markets for identical assets): | Marketable equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	9
Fair Value | Level 2 (Significant other observable inputs):
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	561	423
Fair Value | Level 2 (Significant other observable inputs): | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	367	0
Fair Value | Level 2 (Significant other observable inputs): | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	63	75
Fair Value | Level 2 (Significant other observable inputs): | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	119	348
Fair Value | Level 2 (Significant other observable inputs): | Negotiable certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	12	0
Reported Value Measurement | Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	2,142	4,247
Reported Value Measurement | Cash and Cash Equivalents | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	712	1,183
Reported Value Measurement | Cash and Cash Equivalents | Non-negotiable certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	381	15
Reported Value Measurement | Cash and Cash Equivalents | Level 1 (Quoted prices in active markets for identical assets):
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	878	2,626
Reported Value Measurement | Cash and Cash Equivalents | Level 1 (Quoted prices in active markets for identical assets): | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	814	2,532
Reported Value Measurement | Cash and Cash Equivalents | Level 1 (Quoted prices in active markets for identical assets): | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	64	94
Reported Value Measurement | Cash and Cash Equivalents | Level 1 (Quoted prices in active markets for identical assets): | Marketable equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Reported Value Measurement | Cash and Cash Equivalents | Level 2 (Significant other observable inputs):
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	171	423
Reported Value Measurement | Cash and Cash Equivalents | Level 2 (Significant other observable inputs): | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Reported Value Measurement | Cash and Cash Equivalents | Level 2 (Significant other observable inputs): | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	63	75
Reported Value Measurement | Cash and Cash Equivalents | Level 2 (Significant other observable inputs): | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	108	348
Reported Value Measurement | Cash and Cash Equivalents | Level 2 (Significant other observable inputs): | Negotiable certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Reported Value Measurement | Short-Term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	390	9
Reported Value Measurement | Short-Term Investments | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Reported Value Measurement | Short-Term Investments | Non-negotiable certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Reported Value Measurement | Short-Term Investments | Level 1 (Quoted prices in active markets for identical assets):
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	9
Reported Value Measurement | Short-Term Investments | Level 1 (Quoted prices in active markets for identical assets): | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Reported Value Measurement | Short-Term Investments | Level 1 (Quoted prices in active markets for identical assets): | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Reported Value Measurement | Short-Term Investments | Level 1 (Quoted prices in active markets for identical assets): | Marketable equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	9
Reported Value Measurement | Short-Term Investments | Level 2 (Significant other observable inputs):
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	390	0
Reported Value Measurement | Short-Term Investments | Level 2 (Significant other observable inputs): | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	367	0
Reported Value Measurement | Short-Term Investments | Level 2 (Significant other observable inputs): | U.S. agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	0	0
Reported Value Measurement | Short-Term Investments | Level 2 (Significant other observable inputs): | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	11	0
Reported Value Measurement | Short-Term Investments | Level 2 (Significant other observable inputs): | Negotiable certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	$ 12	$ 0