Stock-Based Compensation - Schedule of Options Exercised, Cash Received, and Related Tax Benefits (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-based Payment Arrangement [Abstract]
Stock options exercised (in shares)	162,400	215,546	685,638	621,917
Cash received upon exercise	$ 12	$ 16	$ 55	$ 44
Related tax benefit realized	$ 3	$ 6	$ 16	$ 15

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Amount of tax benefit from exercise of option under share-based payment arrangement.

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Amount of cash inflow from exercise of option under share-based payment arrangement.

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