Fair Value Measurement of Assets and Liabilities - Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Assets:
Funds receivable and customer accounts	$ 35,104	$ 33,418
Liabilities:
Cash	7,500	3,900
Short-term restricted cash	23	88
Time deposits	1,200	1,600
Carrying value of non-marketable equity securities which do not have readily determinable fair value	1,300	789
Cash and cash equivalents
Assets:
Funds receivable and customer accounts	12,164	13,222
Cash, time deposits and funds receivable
Assets:
Funds receivable and customer accounts	17,000	16,600
Fair value, measurements, recurring basis
Assets:
Cash and cash equivalents	271	867
Funds receivable and customer accounts	18,093	16,771
Derivatives	348	42
Total financial assets	28,527	29,631
Liabilities:
Derivatives	158	410
Fair value, measurements, recurring basis | Cash and cash equivalents
Assets:
Funds receivable and customer accounts	486	1,770
Fair value, measurements, recurring basis | U.S. government and agency securities
Assets:
Funds receivable and customer accounts	9,168	7,933
Fair value, measurements, recurring basis | Foreign government and agency securities
Assets:
Funds receivable and customer accounts	3,233	4,296
Fair value, measurements, recurring basis | Corporate debt securities
Assets:
Funds receivable and customer accounts	3,936	2,135
Fair value, measurements, recurring basis | Asset-backed securities
Assets:
Funds receivable and customer accounts	1,220
Fair value, measurements, recurring basis | Municipal securities
Assets:
Funds receivable and customer accounts	50	637
Fair value, measurements, recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash and cash equivalents	0	0
Funds receivable and customer accounts	0	0
Derivatives	0	0
Total financial assets	2,219	2,443
Liabilities:
Derivatives	0	0
Fair value, measurements, recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and cash equivalents
Assets:
Funds receivable and customer accounts	0	0
Fair value, measurements, recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government and agency securities
Assets:
Funds receivable and customer accounts	0	0
Fair value, measurements, recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign government and agency securities
Assets:
Funds receivable and customer accounts	0	0
Fair value, measurements, recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate debt securities
Assets:
Funds receivable and customer accounts	0	0
Fair value, measurements, recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Asset-backed securities
Assets:
Funds receivable and customer accounts	0
Fair value, measurements, recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Municipal securities
Assets:
Funds receivable and customer accounts	0	0
Fair value, measurements, recurring basis | Significant Other Observable Inputs (Level 2)
Assets:
Cash and cash equivalents	271	867
Funds receivable and customer accounts	18,093	16,771
Derivatives	348	42
Total financial assets	26,308	27,188
Liabilities:
Derivatives	158	410
Fair value, measurements, recurring basis | Significant Other Observable Inputs (Level 2) | Cash and cash equivalents
Assets:
Funds receivable and customer accounts	486	1,770
Fair value, measurements, recurring basis | Significant Other Observable Inputs (Level 2) | U.S. government and agency securities
Assets:
Funds receivable and customer accounts	9,168	7,933
Fair value, measurements, recurring basis | Significant Other Observable Inputs (Level 2) | Foreign government and agency securities
Assets:
Funds receivable and customer accounts	3,233	4,296
Fair value, measurements, recurring basis | Significant Other Observable Inputs (Level 2) | Corporate debt securities
Assets:
Funds receivable and customer accounts	3,936	2,135
Fair value, measurements, recurring basis | Significant Other Observable Inputs (Level 2) | Asset-backed securities
Assets:
Funds receivable and customer accounts	1,220
Fair value, measurements, recurring basis | Significant Other Observable Inputs (Level 2) | Municipal securities
Assets:
Funds receivable and customer accounts	50	637
Fair value, measurements, recurring basis | Short-term investments
Assets:
Investments	4,371	6,689
Fair value, measurements, recurring basis | Short-term investments | U.S. government and agency securities
Assets:
Investments	639	1,510
Fair value, measurements, recurring basis | Short-term investments | Foreign government and agency securities
Assets:
Investments	1,258	277
Fair value, measurements, recurring basis | Short-term investments | Corporate debt securities
Assets:
Investments	2,293	4,902
Fair value, measurements, recurring basis | Short-term investments | Asset-backed securities
Assets:
Investments	181
Fair value, measurements, recurring basis | Short-term investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments	0	0
Fair value, measurements, recurring basis | Short-term investments | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government and agency securities
Assets:
Investments	0	0
Fair value, measurements, recurring basis | Short-term investments | Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign government and agency securities
Assets:
Investments	0	0
Fair value, measurements, recurring basis | Short-term investments | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate debt securities
Assets:
Investments	0	0
Fair value, measurements, recurring basis | Short-term investments | Quoted Prices in Active Markets for Identical Assets (Level 1) | Asset-backed securities
Assets:
Investments	0
Fair value, measurements, recurring basis | Short-term investments | Significant Other Observable Inputs (Level 2)
Assets:
Investments	4,371	6,689
Fair value, measurements, recurring basis | Short-term investments | Significant Other Observable Inputs (Level 2) | U.S. government and agency securities
Assets:
Investments	639	1,510
Fair value, measurements, recurring basis | Short-term investments | Significant Other Observable Inputs (Level 2) | Foreign government and agency securities
Assets:
Investments	1,258	277
Fair value, measurements, recurring basis | Short-term investments | Significant Other Observable Inputs (Level 2) | Corporate debt securities
Assets:
Investments	2,293	4,902
Fair value, measurements, recurring basis | Short-term investments | Significant Other Observable Inputs (Level 2) | Asset-backed securities
Assets:
Investments	181
Fair value, measurements, recurring basis | Long-Term Investments
Assets:
Investments	5,444	5,262
Fair value, measurements, recurring basis | Long-Term Investments | U.S. government and agency securities
Assets:
Investments	582	28
Fair value, measurements, recurring basis | Long-Term Investments | Foreign government and agency securities
Assets:
Investments	910	1,304
Fair value, measurements, recurring basis | Long-Term Investments | Corporate debt securities
Assets:
Investments	1,396	1,259
Fair value, measurements, recurring basis | Long-Term Investments | Asset-backed securities
Assets:
Investments	337	228
Fair value, measurements, recurring basis | Long-Term Investments | Marketable equity securities
Assets:
Investments	2,219	2,443
Fair value, measurements, recurring basis | Long-Term Investments | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments	2,219	2,443
Fair value, measurements, recurring basis | Long-Term Investments | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government and agency securities
Assets:
Investments	0	0
Fair value, measurements, recurring basis | Long-Term Investments | Quoted Prices in Active Markets for Identical Assets (Level 1) | Foreign government and agency securities
Assets:
Investments	0	0
Fair value, measurements, recurring basis | Long-Term Investments | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate debt securities
Assets:
Investments	0	0
Fair value, measurements, recurring basis | Long-Term Investments | Quoted Prices in Active Markets for Identical Assets (Level 1) | Asset-backed securities
Assets:
Investments	0	0
Fair value, measurements, recurring basis | Long-Term Investments | Quoted Prices in Active Markets for Identical Assets (Level 1) | Marketable equity securities
Assets:
Investments	2,219	2,443
Fair value, measurements, recurring basis | Long-Term Investments | Significant Other Observable Inputs (Level 2)
Assets:
Investments	3,225	2,819
Fair value, measurements, recurring basis | Long-Term Investments | Significant Other Observable Inputs (Level 2) | U.S. government and agency securities
Assets:
Investments	582	28
Fair value, measurements, recurring basis | Long-Term Investments | Significant Other Observable Inputs (Level 2) | Foreign government and agency securities
Assets:
Investments	910	1,304
Fair value, measurements, recurring basis | Long-Term Investments | Significant Other Observable Inputs (Level 2) | Corporate debt securities
Assets:
Investments	1,396	1,259
Fair value, measurements, recurring basis | Long-Term Investments | Significant Other Observable Inputs (Level 2) | Asset-backed securities
Assets:
Investments	337	228
Fair value, measurements, recurring basis | Long-Term Investments | Significant Other Observable Inputs (Level 2) | Marketable equity securities
Assets:
Investments	$ 0	$ 0