Fair Value Measurements (Tables)

6 Months Ended

Sep. 30, 2018

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Fair Value, Assets Measured on Recurring Basis [Table Text Block]

			Fair Value Measurements at Reporting Date Using
			Quoted Prices in Active Markets  for Identical Financial Instruments		Significant Other Observable Inputs		Significant Unobservable Inputs
	As of September 30, 2018		(Level 1)		(Level 2)		(Level 3)		Balance Sheet Classification
Assets
Bank and time deposits	$	24	$	24	$	—	$	—	Cash equivalents
Money market funds	1,138		1,138		—		—		Cash equivalents
Available-for-sale securities:
Corporate bonds	762				762		—		Short-term investments and cash equivalents
U.S. Treasury securities	281		281		—		—		Short-term investments and cash equivalents
U.S. agency securities	73		—		73		—		Short-term investments
Commercial paper	392		—		392		—		Short-term investments and cash equivalents
Foreign government securities	79		—		79		—		Short-term investments
Asset-backed securities	121		—		121		—		Short-term investments
Certificates of deposit	21		—		21		—		Short-term investments
Foreign currency derivatives	49		—		49		—		Other current assets and other assets
Deferred compensation plan assets (a)	12		12		—		—		Other assets
Total assets at fair value	$	2,952	$	1,455	$	1,497	$	—
Liabilities
Contingent consideration (b)	$	124	$	—	$	—	$	124	Accrued and other current liabilities and other liabilities
Foreign currency derivatives	10		—		10		—		Accrued and other current liabilities and other liabilities
Deferred compensation plan liabilities (a)	12		12		—		—		Other liabilities
Total liabilities at fair value	$	146	$	12	$	10	$	124

			Fair Value Measurements at Reporting Date Using
			Quoted Prices in Active Markets  for Identical Financial Instruments		Significant Other Observable Inputs		Significant Unobservable Inputs
	As of March 31, 2018		(Level 1)		(Level 2)		(Level 3)		Balance Sheet Classification
Assets
Bank and time deposits	$	286	$	286	$	—	$	—	Cash equivalents
Money market funds	1,876		1,876		—		—		Cash equivalents
Available-for-sale securities:
Corporate bonds	624		—		624		—		Short-term investments
U.S. Treasury securities	210		210		—		—		Short-term investments
U.S. agency securities	78		—		78		—		Short-term investments
Commercial paper	150		—		150		—		Short-term investments and cash equivalents
Foreign government securities	52		—		52		—		Short-term investments
Certificates of Deposit	2		—		2		—		Cash equivalents
Foreign currency derivatives	4		—		4		—		Other current assets and other assets
Deferred compensation plan assets (a)	10		10		—		—		Other assets
Total assets at fair value	$	3,292	$	2,382	$	910	$	—
Liabilities
Contingent consideration (b)	$	122	$	—	$	—	$	122	Other liabilities
Foreign currency derivatives	56		—		56		—		Accrued and other current liabilities and other liabilities
Deferred compensation plan liabilities (a)	11		11		—		—		Other liabilities
Total liabilities at fair value	$	189	$	11	$	56	$	122

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
		Contingent Consideration
Balance as of March 31, 2018		$	122
Additions		—
Change in fair value(c)		2
Balance as of September 30, 2018		$	124