DEBT - Schedule of Outstanding Debt (Details) € in Millions, $ in Millions	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Apr. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 EUR (€)	Aug. 31, 2017	Mar. 31, 2017	May 31, 2016	Nov. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Aug. 31, 2014 USD ($)	May 31, 2013 USD ($)
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (172)			$ (71)
Long-term debt:
Outstanding Principal Amount	11,201			7,711
Long-term debt	11,029			7,640
0.35% Convertible Senior Notes due June 2020 | Convertible Senior Notes
Long-term debt:
Face amount of debt													$ 1,000
Stated interest rate													0.35%
0.35% Convertible Senior Notes due June 2020 | Convertible Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost				(12)
Carrying Value				988
Long-term debt:
Outstanding Principal Amount				$ 1,000
Stated interest rate				0.35%	0.35%
0.9% Convertible Senior Notes due September 2021 | Convertible Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost				$ (39)
Long-term debt:
Outstanding Principal Amount				1,000
Long-term debt				$ 961
Face amount of debt												$ 1,000
Stated interest rate				0.90%	0.90%							0.90%
0.9% Convertible Senior Notes due September 2021 | Convertible Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	(15)
Carrying Value	985
Long-term debt:
Outstanding Principal Amount	$ 1,000
Stated interest rate	0.90%	0.90%
0.8% (€1 Billion) Senior Notes due March 2022 | Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (1)			$ (3)
Long-term debt:
Outstanding Principal Amount	1,223			1,123
Long-term debt	$ 1,222			$ 1,120
Face amount of debt | €		€ 1,000			€ 1,000
Stated interest rate	0.80%	0.80%		0.80%	0.80%		0.80%
2.15% (€750 Million) Senior Notes due November 2022 | Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (4)			$ (3)
Long-term debt:
Outstanding Principal Amount	919			842
Long-term debt	$ 915			$ 839
Face amount of debt | €		€ 750			€ 750
Stated interest rate	2.15%	2.15%		2.15%	2.15%				2.15%
2.75% Senior Notes due March 2023 | Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (1)			$ (2)
Long-term debt:
Outstanding Principal Amount	500			500
Long-term debt	$ 499			$ 498
Stated interest rate	2.75%	2.75%		2.75%	2.75%	2.75%
2.375% (€1 Billion) Senior Notes due September 2024 | Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (7)			$ (9)
Long-term debt:
Outstanding Principal Amount	1,223			1,123
Long-term debt	$ 1,216			$ 1,114
Face amount of debt | €		€ 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
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (2)			$ (2)
Long-term debt:
Outstanding Principal Amount	500			500
Long-term debt	$ 498			$ 498
Stated interest rate	3.65%	3.65%		3.65%	3.65%					3.65%
4.1% Senior Notes due April 2025 | Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (5)
Long-term debt:
Outstanding Principal Amount	1,000		$ 1,000
Long-term debt	$ 995
Stated interest rate	4.10%	4.10%	4.10%
0.75% Convertible Senior Notes due May 2025 | Convertible Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (128)
Long-term debt:
Outstanding Principal Amount	863
Long-term debt	$ 735
Face amount of debt			$ 863
Stated interest rate	0.75%	0.75%	0.75%
3.6% Senior Notes due June 2026 | Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (4)			$ (5)
Long-term debt:
Outstanding Principal Amount	1,000			1,000
Long-term debt	$ 996			$ 995
Stated interest rate	3.60%	3.60%		3.60%	3.60%			3.60%
1.8% (€1 Billion) Senior Notes due March 2027 | Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (2)			$ (5)
Long-term debt:
Outstanding Principal Amount	1,223			1,123
Long-term debt	$ 1,221			$ 1,118
Face amount of debt | €		€ 1,000			€ 1,000
Stated interest rate	1.80%	1.80%		1.80%	1.80%					1.80%
4.5% Senior Notes due April 2027 | Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (5)
Long-term debt:
Outstanding Principal Amount	750		$ 750
Long-term debt	$ 745
Stated interest rate	4.50%	4.50%	4.50%
3.55% Senior Notes due March 2028 | Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (2)			$ (3)
Long-term debt:
Outstanding Principal Amount	500			500
Long-term debt	$ 498			$ 497
Stated interest rate	3.55%	3.55%		3.55%	3.55%	3.55%
4.625% Senior Notes due April 2030 | Senior Notes
Current Liabilities:
Unamortized Debt Discount and Debt Issuance Cost	$ (11)
Long-term debt:
Outstanding Principal Amount	1,500		$ 1,500
Long-term debt	$ 1,489
Stated interest rate	4.625%	4.625%	4.625%