DEBT - Schedule of Outstanding Debt (Details) € in Millions, $ in Millions	Mar. 31, 2021 USD ($)	Mar. 31, 2021 EUR (€)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Apr. 30, 2020 USD ($)	Aug. 31, 2017	Mar. 31, 2017	May 31, 2016	Nov. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Aug. 31, 2014 USD ($)
Current Liabilities:
Carrying Value	$ 3,905		$ 985
Long-term debt:
Carrying Value	9,930		11,029
Total long-term debt
Long-term debt:
Outstanding Principal  Amount	10,093		11,201
Unamortized Debt Discount and Debt Issuance Cost	(163)		(172)
Carrying Value	9,930		11,029
Total short-term debt
Current Liabilities:
Carrying Value	3,905
Long-term debt:
Outstanding Principal  Amount	3,925
Unamortized Debt Discount and Debt Issuance Cost	(20)
0.9% Convertible Senior Notes due September 2021 | Convertible Debt
Long-term debt:
Aggregate principal amount												$ 1,000
Stated interest rate												0.90%
0.9% Convertible Senior Notes due September 2021 | Convertible Debt
Current Liabilities:
Carrying Value	991		985
Long-term debt:
Outstanding Principal  Amount	1,000		1,000
Unamortized Debt Discount and Debt Issuance Cost	$ (9)		$ (15)
Stated interest rate	0.90%	0.90%	0.90%	0.90%
0.8% (€1 billion) Senior Notes due March 2022 | Senior Notes
Long-term debt:
Outstanding Principal  Amount			$ 1,223
Unamortized Debt Discount and Debt Issuance Cost			(1)
Carrying Value			$ 1,222
Aggregate principal amount | €				€ 1,000
Stated interest rate			0.80%	0.80%			0.80%
0.8% (€1 billion) Senior Notes due March 2022 | Senior Notes
Current Liabilities:
Carrying Value	$ 1,173
Long-term debt:
Outstanding Principal  Amount	1,175
Unamortized Debt Discount and Debt Issuance Cost	$ (2)
Aggregate principal amount | €		€ 1,000
Stated interest rate	0.80%	0.80%
4.1% Senior Notes due April 2025 | Senior Notes
Long-term debt:
Outstanding Principal  Amount			$ 1,000
Unamortized Debt Discount and Debt Issuance Cost			(5)
Carrying Value			$ 995
Stated interest rate			4.10%	4.10%	4.10%
4.1% Senior Notes due April 2025 | Senior Notes
Current Liabilities:
Carrying Value	$ 996
Long-term debt:
Outstanding Principal  Amount	1,000
Unamortized Debt Discount and Debt Issuance Cost	$ (4)
Stated interest rate	4.10%	4.10%
4.5% Senior Notes due April 2027 | Senior Notes
Long-term debt:
Outstanding Principal  Amount			$ 750
Unamortized Debt Discount and Debt Issuance Cost			(5)
Carrying Value			$ 745
Stated interest rate			4.50%	4.50%	4.50%
4.5% Senior Notes due April 2027 | Senior Notes
Current Liabilities:
Carrying Value	$ 745
Long-term debt:
Outstanding Principal  Amount	750
Unamortized Debt Discount and Debt Issuance Cost	$ (5)
Stated interest rate	4.50%	4.50%
2.15% (€750 million) Senior Notes due November 2022 | Senior Notes
Long-term debt:
Outstanding Principal  Amount	$ 881		$ 919
Unamortized Debt Discount and Debt Issuance Cost	(2)		(4)
Carrying Value	$ 879		$ 915
Aggregate principal amount | €		€ 750		€ 750
Stated interest rate	2.15%	2.15%	2.15%	2.15%					2.15%
2.75% Senior Notes due March 2023 | Senior Notes
Long-term debt:
Outstanding Principal  Amount	$ 500		$ 500
Unamortized Debt Discount and Debt Issuance Cost	(1)		(1)
Carrying Value	$ 499		$ 499
Stated interest rate	2.75%	2.75%	2.75%	2.75%		2.75%
2.375% (€1 billion) Senior Notes due September 2024 | Senior Notes
Long-term debt:
Outstanding Principal  Amount	$ 1,175		$ 1,223
Unamortized Debt Discount and Debt Issuance Cost	(6)		(7)
Carrying Value	$ 1,169		$ 1,216
Aggregate principal amount | €		€ 1,000		€ 1,000
Stated interest rate	2.375%	2.375%	2.375%	2.375%							2.375%
3.65% Senior Notes due March 2025 | Senior Notes
Long-term debt:
Outstanding Principal  Amount	$ 500		$ 500
Unamortized Debt Discount and Debt Issuance Cost	(2)		(2)
Carrying Value	$ 498		$ 498
Stated interest rate	3.65%	3.65%	3.65%	3.65%						3.65%
0.1% (€950 million) Senior Notes due March 2025 | Senior Notes
Long-term debt:
Outstanding Principal  Amount	$ 1,118	€ 950
Unamortized Debt Discount and Debt Issuance Cost	(6)
Carrying Value	$ 1,112
Aggregate principal amount | €		€ 950
Stated interest rate	0.10%	0.10%
0.75% Convertible Senior Notes due May 2025 | Convertible Debt
Long-term debt:
Outstanding Principal  Amount	$ 863		$ 863
Unamortized Debt Discount and Debt Issuance Cost	(121)		(128)
Carrying Value	$ 742		$ 735
Aggregate principal amount					$ 863
Stated interest rate	0.75%	0.75%	0.75%	0.75%	0.75%
3.6% Senior Notes due June 2026 | Senior Notes
Long-term debt:
Outstanding Principal  Amount	$ 1,000		$ 1,000
Unamortized Debt Discount and Debt Issuance Cost	(4)		(4)
Carrying Value	$ 996		$ 996
Stated interest rate	3.60%	3.60%	3.60%	3.60%				3.60%
1.8% (€1 billion) Senior Notes due March 2027 | Senior Notes
Long-term debt:
Outstanding Principal  Amount	$ 1,175		$ 1,223
Unamortized Debt Discount and Debt Issuance Cost	(3)		(2)
Carrying Value	$ 1,172		$ 1,221
Aggregate principal amount | €		€ 1,000		€ 1,000
Stated interest rate	1.80%	1.80%	1.80%	1.80%						1.80%
3.55% Senior Notes due March 2028 | Senior Notes
Long-term debt:
Outstanding Principal  Amount	$ 500		$ 500
Unamortized Debt Discount and Debt Issuance Cost	(2)		(2)
Carrying Value	$ 498		$ 498
Stated interest rate	3.55%	3.55%	3.55%	3.55%		3.55%
0.5% (€750 million) Senior Notes due March 2028 | Senior Notes
Long-term debt:
Outstanding Principal  Amount	$ 881	€ 750
Unamortized Debt Discount and Debt Issuance Cost	(5)
Carrying Value	$ 876
Aggregate principal amount | €		€ 750
Stated interest rate	0.50%	0.50%
4.625% Senior Notes due April 2030 | Senior Notes
Long-term debt:
Outstanding Principal  Amount	$ 1,500		$ 1,500
Unamortized Debt Discount and Debt Issuance Cost	(11)		(11)
Carrying Value	$ 1,489		$ 1,489
Stated interest rate	4.625%	4.625%	4.625%	4.625%	4.625%