DEBT (Outstanding Debt) (Details)	1 Months Ended			3 Months Ended		12 Months Ended
	Apr. 30, 2020 USD ($) Days $ / shares	Aug. 31, 2014 USD ($) Days $ / shares	May 31, 2013 USD ($) Days $ / shares	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Mar. 31, 2020 EUR (€)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 EUR (€)	Aug. 31, 2017	Mar. 31, 2017	May 31, 2016	Nov. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Jun. 30, 2013 USD ($)
Debt Instrument
Convertible debt				$ 4,000,000					$ 0
Outstanding Principal Amount, Long-Term Debt				7,615,000,000					7,711,000,000
Unamortized Debt Discount and Debt Issuance Cost				(62,000,000)					(71,000,000)
Long-term Debt				$ 7,553,000,000					$ 7,640,000,000
0.35% Convertible Senior Notes due June 2020
Description of Senior Notes
Aggregate principal amount			$ 1,000,000,000.0
Interest rate on long-term debt			0.35%	0.35%				0.35%	0.35%	0.35%
Debt financing costs paid							$ 1,000,000
Convertible debt conversion price (in dollars per share) | $ / shares			$ 1,315.10
Ratio of closing share price to conversion price as a condition for conversion of the convertible notes, minimum			150.00%
if-converted value over the aggregate principal amount				$ 92,000,000
Unamortized debt discount			$ 20,000,000
Effective interest rate at debt origination or modification			3.13%
Debt discount related to convertible notes, net of tax																	$ 92,000,000
Debt discount related to convertible notes, before tax																	$ 154,000,000
Amortization of debt discount included in interest expense				1,000,000	$ 1,000,000
0.9% Convertible Senior Notes due September 2021
Debt Instrument
Outstanding Principal Amount, Long-Term Debt				1,000,000,000					$ 1,000,000,000
Unamortized Debt Discount and Debt Issuance Cost				(33,000,000)					(39,000,000)
Long-term Debt				$ 967,000,000					$ 961,000,000
Description of Senior Notes
Aggregate principal amount		$ 1,000,000,000.0
Interest rate on long-term debt		0.90%		0.90%				0.90%	0.90%	0.90%
Debt financing costs paid						$ 11,000,000
Convertible debt conversion price (in dollars per share) | $ / shares		$ 2,055.50
Ratio of closing share price to conversion price as a condition for conversion of the convertible notes, minimum		150.00%
Effective interest rate at debt origination or modification		3.18%
Debt discount related to convertible notes, net of tax						83,000,000
Debt discount related to convertible notes, before tax						$ 143,000,000
0.8% (€1 Billion) Senior Notes due March 2022
Debt Instrument
Outstanding Principal Amount, Long-Term Debt				$ 1,097,000,000					$ 1,123,000,000
Unamortized Debt Discount and Debt Issuance Cost				(3,000,000)					(3,000,000)
Long-term Debt				$ 1,094,000,000					$ 1,120,000,000
Description of Senior Notes
Aggregate principal amount | €								€ 1,000,000,000		€ 1,000,000,000
Interest rate on long-term debt				0.80%				0.80%	0.80%	0.80%
Effective interest rate at debt origination or modification												0.84%
2.15% (€750 Million) Senior Notes due November 2022
Debt Instrument
Outstanding Principal Amount, Long-Term Debt				$ 824,000,000					$ 842,000,000
Unamortized Debt Discount and Debt Issuance Cost				(2,000,000)					(3,000,000)
Long-term Debt				$ 822,000,000					$ 839,000,000
Description of Senior Notes
Aggregate principal amount | €								€ 750,000,000		€ 750,000,000
Interest rate on long-term debt				2.15%				2.15%	2.15%	2.15%
Effective interest rate at debt origination or modification														2.20%
2.75% Senior Notes due March 2023
Debt Instrument
Outstanding Principal Amount, Long-Term Debt				$ 500,000,000					$ 500,000,000
Unamortized Debt Discount and Debt Issuance Cost				(2,000,000)					(2,000,000)
Long-term Debt				$ 498,000,000					$ 498,000,000
Description of Senior Notes
Interest rate on long-term debt				2.75%				2.75%	2.75%	2.75%
Effective interest rate at debt origination or modification											2.78%
2.375% (€1 Billion) Senior Notes due September 2024
Debt Instrument
Outstanding Principal Amount, Long-Term Debt				$ 1,097,000,000					$ 1,123,000,000
Unamortized Debt Discount and Debt Issuance Cost				(8,000,000)					(9,000,000)
Long-term Debt				$ 1,089,000,000					$ 1,114,000,000
Description of Senior Notes
Aggregate principal amount | €								€ 1,000,000,000		€ 1,000,000,000
Interest rate on long-term debt				2.375%				2.375%	2.375%	2.375%
Effective interest rate at debt origination or modification																2.48%
3.65% Senior Notes Due March 2025 [Member]
Debt Instrument
Outstanding Principal Amount, Long-Term Debt				$ 500,000,000					$ 500,000,000
Unamortized Debt Discount and Debt Issuance Cost				(2,000,000)					(2,000,000)
Long-term Debt				$ 498,000,000					$ 498,000,000
Description of Senior Notes
Interest rate on long-term debt				3.65%				3.65%	3.65%	3.65%
Effective interest rate at debt origination or modification															3.68%
3.6% Senior Notes due June 2026
Debt Instrument
Outstanding Principal Amount, Long-Term Debt				$ 1,000,000,000					$ 1,000,000,000
Unamortized Debt Discount and Debt Issuance Cost				(5,000,000)					(5,000,000)
Long-term Debt				$ 995,000,000					$ 995,000,000
Description of Senior Notes
Interest rate on long-term debt				3.60%				3.60%	3.60%	3.60%
Effective interest rate at debt origination or modification													3.62%
1.8% (€1 Billion) Senior Notes due March 2027
Debt Instrument
Outstanding Principal Amount, Long-Term Debt				$ 1,097,000,000					$ 1,123,000,000
Unamortized Debt Discount and Debt Issuance Cost				(4,000,000)					(5,000,000)
Long-term Debt				$ 1,093,000,000					$ 1,118,000,000
Description of Senior Notes
Aggregate principal amount | €								€ 1,000,000,000		€ 1,000,000,000
Interest rate on long-term debt				1.80%				1.80%	1.80%	1.80%
Effective interest rate at debt origination or modification															1.80%
3.55% Senior Notes due March 2028
Debt Instrument
Outstanding Principal Amount, Long-Term Debt				$ 500,000,000					$ 500,000,000
Unamortized Debt Discount and Debt Issuance Cost				(3,000,000)					(3,000,000)
Long-term Debt				$ 497,000,000					$ 497,000,000
Description of Senior Notes
Interest rate on long-term debt				3.55%				3.55%	3.55%	3.55%
Effective interest rate at debt origination or modification											3.56%
Convertible Debt
Description of Senior Notes
Interest expense related to debt				$ 15,000,000	15,000,000
Amortization of debt discount included in interest expense				12,000,000	12,000,000
Coupon Interest expense				$ 3,000,000	$ 3,000,000
Debt, weighted average interest rate				3.20%	3.20%
Other Long-term Debt
Debt Instrument
Long-term Debt				$ 6,600,000,000					$ 6,700,000,000
Description of Senior Notes
Interest expense related to debt				42,000,000	$ 42,000,000
Coupon Interest expense				40,000,000	$ 40,000,000
Minimum | 0.35% Convertible Senior Notes due June 2020
Description of Senior Notes
Minimum and Maximum consecutive days the closing sales price of common stock must exceed a specified percentage of conversion price to trigger conversion feature of note (in days) | Days			20
Additional payment to debt holder, settled In shares, aggregate value			$ 0
Minimum | 0.9% Convertible Senior Notes due September 2021
Description of Senior Notes
Minimum and Maximum consecutive days the closing sales price of common stock must exceed a specified percentage of conversion price to trigger conversion feature of note (in days) | Days		20
Additional payment to debt holder, settled In shares, aggregate value		$ 0
Maximum | 0.35% Convertible Senior Notes due June 2020
Description of Senior Notes
Minimum and Maximum consecutive days the closing sales price of common stock must exceed a specified percentage of conversion price to trigger conversion feature of note (in days) | Days			30
Additional payment to debt holder, settled In shares, aggregate value			$ 397,000,000
Maximum | 0.9% Convertible Senior Notes due September 2021
Description of Senior Notes
Minimum and Maximum consecutive days the closing sales price of common stock must exceed a specified percentage of conversion price to trigger conversion feature of note (in days) | Days		30
Additional payment to debt holder, settled In shares, aggregate value		$ 375,000,000
Level 2
Description of Senior Notes
Estimated market value of outstanding debt				8,700,000,000					9,800,000,000
Designated as Hedging Instrument | Minimum | Euro-Denominated Debt
Description of Senior Notes
Notional amount of nonderivative instruments				2,100,000,000
Designated as Hedging Instrument | Maximum | Euro-Denominated Debt
Description of Senior Notes
Notional amount of nonderivative instruments				3,200,000,000
Short-term Debt [Member] | 0.35% Convertible Senior Notes due June 2020
Debt Instrument
Outstanding Principal Amount, Short-Term Debt				1,000,000,000					1,000,000,000
Unamortized Debt Discount and Debt Issuance Cost				(5,000,000)					(12,000,000)
Carrying Value, Short-term debt				995,000,000					988,000,000
Recurring Basis
Debt Instrument
Debt Securities, Available-for-sale, Amortized Cost				8,463,000,000					10,751,000,000
Recurring Basis | Level 3
Debt Instrument
Debt Securities, Available-for-sale, Amortized Cost				230,000,000					250,000,000
Description of Senior Notes
Carrying Value				230,000,000					250,000,000
Debt Securities, Available-for-sale, Unrealized Loss				20,000,000
Recurring Basis | Level 2
Debt Instrument
Debt Securities, Available-for-sale, Amortized Cost				872,000,000					2,945,000,000
Long-term Investments | Recurring Basis
Debt Instrument
Debt Securities, Available-for-sale, Amortized Cost				230,000,000					250,000,000
Long-term Investments | Recurring Basis | Level 3
Debt Instrument
Debt Securities, Available-for-sale, Amortized Cost				230,000,000					250,000,000
Long-term Investments | Recurring Basis | Level 2
Debt Instrument
Debt Securities, Available-for-sale, Amortized Cost				0					0
Redeemable Convertible Preferred Stock [Member] | Long-term Investments
Description of Senior Notes
Carrying Value				$ 230,000,000					$ 250,000,000
Subsequent Event | 3.65% Senior Notes due March 2025
Debt Instrument
Outstanding Principal Amount, Long-Term Debt	$ 1,000,000,000
Description of Senior Notes
Interest rate on long-term debt	4.10%
Subsequent Event | 0.75% Senior Convertible Notes Due May 2025 [Member] [Member]
Description of Senior Notes
Aggregate principal amount	$ 863,000,000
Interest rate on long-term debt	0.75%
Convertible debt conversion price (in dollars per share) | $ / shares	$ 1,886.44
Ratio of closing share price to conversion price as a condition for conversion of the convertible notes, minimum	130.00%
Subsequent Event | 4.5% Senior Notes Due April 2027 [Member]
Debt Instrument
Outstanding Principal Amount, Long-Term Debt	$ 750,000,000
Description of Senior Notes
Interest rate on long-term debt	4.50%
Subsequent Event | 4.625% Senior Notes Due April 2030 [Member]
Debt Instrument
Outstanding Principal Amount, Long-Term Debt	$ 1,500,000,000
Description of Senior Notes
Interest rate on long-term debt	4.625%
Subsequent Event | Minimum | 0.75% Senior Convertible Notes Due May 2025 [Member] [Member]
Description of Senior Notes
Minimum and Maximum consecutive days the closing sales price of common stock must exceed a specified percentage of conversion price to trigger conversion feature of note (in days) | Days	20
Additional payment to debt holder, settled In shares, aggregate value	$ 0
Subsequent Event | Maximum | 0.75% Senior Convertible Notes Due May 2025 [Member] [Member]
Description of Senior Notes
Minimum and Maximum consecutive days the closing sales price of common stock must exceed a specified percentage of conversion price to trigger conversion feature of note (in days) | Days	30
Additional payment to debt holder, settled In shares, aggregate value	$ 273,000,000