Goodwill and Acquisition-Related Intangibles - Additional Information (Details) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill impairment loss	$ 0	$ 0	$ 0
Amortization of acquisition-related intangibles	$ 318,000,000	$ 318,000,000	$ 319,000,000

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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