STOCKHOLDERS' EQUITY - Summary of Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 18,964	$ 22,179	$ 18,221	$ 22,650
Other comprehensive income (loss)	1	24	99	(15)
Ending balance	19,710	18,142	19,710	18,142
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	38	46	(60)	85
Net unrealized gain (loss)			57	37
Reclassifications to net income (loss)			42	(52)
Other comprehensive income (loss)	1	24	99	(15)
Ending balance	39	70	39	70
Foreign Currency Translation, Net of Tax
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance			51	53
Net unrealized gain (loss)			5	(35)
Reclassifications to net income (loss)			0	0
Other comprehensive income (loss)			5	(35)
Ending balance	56	18	56	18
Unrealized Gains and Losses on Available-for-Sale Debt Securities, Net of Tax
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance			2	1
Net unrealized gain (loss)			(3)	51
Reclassifications to net income (loss)			0	(13)
Other comprehensive income (loss)			(3)	38
Ending balance	(1)	39	(1)	39
Unrealized Gains and Losses on Cash Flow Hedges, Net of Tax
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance			(113)	31
Net unrealized gain (loss)			55	21
Reclassifications to net income (loss)			42	(39)
Other comprehensive income (loss)			97	(18)
Ending balance	$ (16)	$ 13	$ (16)	$ 13