Acquisitions - Purchase Price Allocation (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jul. 29, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 35,517		$ 5,702
First Data
Business Acquisition [Line Items]
Cash and cash equivalents		$ 311
Trade accounts receivable		1,754
Prepaid expenses and other current assets		1,072
Settlement assets		10,397
Property and equipment		1,233
Finite-lived intangibles assets		16,028
Goodwill		29,955
Investments in unconsolidated affiliates		2,637
Other long-term assets		1,154
Total assets acquired		64,541
Accounts payable and accrued expenses		1,515
Short-term and current maturities of long-term debt		237
Contract liabilities		74
Settlement obligations		10,397
Deferred income taxes	3,400	3,388
Long-term contract liabilities		16
Long-term debt and other long-term liabilities		1,232
Total liabilities assumed		16,859
Net assets acquired		47,682
Redeemable noncontrolling interest		88
Noncontrolling interests		1,119
Total purchase price		46,475
Elan Financial Services
Business Acquisition [Line Items]
Trade accounts receivable	20
Prepaid expenses and other current assets	98
Property and equipment	9
Intangible assets	373
Finite-lived intangibles assets	373
Goodwill	214
Accounts payable and other current liabilities	(55)
Net assets acquired	659
Customer relationships | First Data
Business Acquisition [Line Items]
Finite-lived intangibles assets		13,637
Customer relationships | Elan Financial Services
Business Acquisition [Line Items]
Finite-lived intangibles assets	$ 370
Other intangible assets | First Data
Business Acquisition [Line Items]
Finite-lived intangibles assets		$ 2,391