Fair Value Measurements (Valuation Of Financial Instruments By Pricing Categories) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2016	Dec. 31, 2015
ASSETS
Available-for-sale Securities, Current			$ 507	$ 700
Investments Fair Value Disclosure			7,618	4,247
Liabilities
Financial and Nonfinancial Liabilities, Fair Value Disclosure			168	152
Interest rate swap liability
ASSETS
Derivative Asset			0	0
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents			6,976	3,379
ASSETS
Investments Fair Value Disclosure			7,061	3,461
Fair Value Liabilities Measured On Recurring Basis Deferred Compensation Plan Liabilities			85	82
Liabilities
Financial and Nonfinancial Liabilities, Fair Value Disclosure			85	82
Fair Value, Inputs, Level 1 | Trading marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading marketable securities			85	82
Fair Value, Inputs, Level 2
ASSETS
Investments Fair Value Disclosure			557	786
Liabilities
Financial and Nonfinancial Liabilities, Fair Value Disclosure			29	14
Fair Value, Inputs, Level 2 | Foreign currency exchange forward contracts
ASSETS
Derivative Asset			12	69
Liabilities
Foreign currency exchange forward contracts			29	10
Fair Value, Inputs, Level 2 | Interest rate swap liability
ASSETS
Derivative Asset			35	15
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration [Abstract]
Derivative Liability			0	4
Fair Value, Inputs, Level 2 | Available-for-sale marketable securities
ASSETS
Available-for-sale Securities, Current			510	702
Fair Value, Inputs, Level 2 | Available-for-sale marketable securities | Corporate and asset-backed debt securities
ASSETS
Available-for-sale Securities, Current			184	214
Fair Value, Inputs, Level 2 | Available-for-sale marketable securities | Foreign government debt securities
ASSETS
Available-for-sale Securities, Current			93	96
Fair Value, Inputs, Level 2 | Available-for-sale marketable securities | United States agency debt securities
ASSETS
Available-for-sale Securities, Current			77	120
Fair Value, Inputs, Level 2 | Available-for-sale marketable securities | United States treasury debt securities
ASSETS
Available-for-sale Securities, Current			139	264
Fair Value, Inputs, Level 2 | Available-for-sale marketable securities | Certificates of deposit
ASSETS
Available-for-sale Securities, Current			17	8
Fair Value, Inputs, Level 3
Liabilities
Financial and Nonfinancial Liabilities, Fair Value Disclosure			54	56
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration [Abstract]
Beginning balance	$ 56	$ 48
Additions	6	11
Losses included in earnings	(3)	0
Settlements	(5)	(3)
Balance at the end of the period	54	56
Total liabilities measured at fair value	$ 56	$ 48	$ 54	$ 56