FUNDS RECEIVABLE AND CUSTOMER ACCOUNTS AND INVESTMENTS - Available-for-sale Debt Securities in Continuous Loss Position (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Fair Value
Less than 12 months	$ 9,841	$ 10,155
12 months or longer	9,063	10,282
Total	18,904	20,437
Gross Unrealized Losses
Less than 12 months	(37)	(150)
12 months or longer	(259)	(442)
Total	(296)	(592)
Funds receivable and customer accounts | U.S. government and agency securities
Fair Value
Less than 12 months	3,534	3,730
12 months or longer	4,504	4,246
Total	8,038	7,976
Gross Unrealized Losses
Less than 12 months	(22)	(89)
12 months or longer	(124)	(163)
Total	(146)	(252)
Funds receivable and customer accounts | Foreign government and agency securities
Fair Value
Less than 12 months	102	410
12 months or longer	513	997
Total	615	1,407
Gross Unrealized Losses
Less than 12 months	(1)	(10)
12 months or longer	(15)	(34)
Total	(16)	(44)
Funds receivable and customer accounts | Corporate debt securities
Fair Value
Less than 12 months	124	9
12 months or longer	1,346	1,545
Total	1,470	1,554
Gross Unrealized Losses
Less than 12 months	0	(1)
12 months or longer	(38)	(81)
Total	(38)	(82)
Funds receivable and customer accounts | Asset-backed securities
Fair Value
Less than 12 months	702	773
12 months or longer	337	508
Total	1,039	1,281
Gross Unrealized Losses
Less than 12 months	(3)	(12)
12 months or longer	(2)	(14)
Total	(5)	(26)
Funds receivable and customer accounts | Municipal securities
Fair Value
Less than 12 months	389	264
12 months or longer	155	50
Total	544	314
Gross Unrealized Losses
Less than 12 months	(4)	(3)
12 months or longer	(2)	0
Total	(6)	(3)
Funds receivable and customer accounts | Commercial paper
Fair Value
Less than 12 months	2,682	3,079
12 months or longer	0	0
Total	2,682	3,079
Gross Unrealized Losses
Less than 12 months	(3)	(14)
12 months or longer	0	0
Total	(3)	(14)
Short-term investments | U.S. government and agency securities
Fair Value
Less than 12 months	25	345
12 months or longer	150	73
Total	175	418
Gross Unrealized Losses
Less than 12 months	0	0
12 months or longer	(6)	(3)
Total	(6)	(3)
Short-term investments | Foreign government and agency securities
Fair Value
Less than 12 months	0	61
12 months or longer	356	362
Total	356	423
Gross Unrealized Losses
Less than 12 months	0	0
12 months or longer	(12)	(11)
Total	(12)	(11)
Short-term investments | Corporate debt securities
Fair Value
Less than 12 months	307	97
12 months or longer	793	465
Total	1,100	562
Gross Unrealized Losses
Less than 12 months	0	(2)
12 months or longer	(21)	(12)
Total	(21)	(14)
Short-term investments | Asset-backed securities
Fair Value
Less than 12 months	188	175
12 months or longer	132	217
Total	320	392
Gross Unrealized Losses
Less than 12 months	(2)	(2)
12 months or longer	(5)	(7)
Total	(7)	(9)
Short-term investments | Commercial paper
Fair Value
Less than 12 months	1,537	224
12 months or longer	0	0
Total	1,537	224
Gross Unrealized Losses
Less than 12 months	(1)	0
12 months or longer	0	0
Total	(1)	0
Long-Term Investments | U.S. government and agency securities
Fair Value
Less than 12 months	0	0
12 months or longer	316	457
Total	316	457
Gross Unrealized Losses
Less than 12 months	0	0
12 months or longer	(20)	(36)
Total	(20)	(36)
Long-Term Investments | Foreign government and agency securities
Fair Value
Less than 12 months	0	31
12 months or longer	32	333
Total	32	364
Gross Unrealized Losses
Less than 12 months	0	(2)
12 months or longer	(2)	(20)
Total	(2)	(22)
Long-Term Investments | Corporate debt securities
Fair Value
Less than 12 months	0	85
12 months or longer	199	834
Total	199	919
Gross Unrealized Losses
Less than 12 months	0	(6)
12 months or longer	(11)	(52)
Total	(11)	(58)
Long-Term Investments | Asset-backed securities
Fair Value
Less than 12 months	251	872
12 months or longer	230	195
Total	481	1,067
Gross Unrealized Losses
Less than 12 months	(1)	(9)
12 months or longer	(1)	(9)
Total	$ (2)	$ (18)