Share-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Millions	9 Months Ended
	Sep. 30, 2019 USD ($) $ / shares shares
Shares
Stock options outstanding - balance at beginning of period (in shares) | shares	12,052
Converted First Data stock options (in shares) | shares	7,591
Granted (in shares) | shares	1,177
Forfeited (in shares) | shares	(158)
Exercised (in shares) | shares	(3,265)
Stock options outstanding - balance at end of period (in shares) | shares	17,397
Stock options exercisable (in shares) | shares	14,531
Weighted-Average Exercise Price
Stock options outstanding - balance at beginning of period (in dollars per shares) | $ / shares	$ 33.96
Converted First Data stock options (in dollars per share) | $ / shares	62.54
Granted (in dollars per share) | $ / shares	84.77
Forfeited (in dollars per share) | $ / shares	68.17
Exercised (in dollars per share) | $ / shares	35.94
Stock options outstanding - balance at end of period (in dollars per shares) | $ / shares	49.19
Stock options exercisable (in dollars per share) | $ / shares	$ 45.00
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Term, Stock options outstanding	5 years 10 days
Weighted Average Remaining Contractual Term, Stock options exercisable	4 years 4 months 13 days
Aggregate Intrinsic Value, Stock options outstanding | $	$ 1,079
Aggregate Intrinsic Value, Stock options exercisable | $	$ 986