Goodwill and Acquired Intangibles - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Amortization expense for acquired finite lived intangible assets	$ 271	$ 284	$ 296
Amortization of finite lived intangible assets in 2021	290
Amortization of finite lived intangible assets in 2022	252
Amortization of finite lived intangible assets in 2023	249
Amortization of finite lived intangible assets in 2024	245
Amortization of finite lived intangible assets in 2025	223
Amortization of finite lived intangible assets after 2025	$ 866
Minimum
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets are amortized	3 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets are amortized	20 years
Customer programs | Minimum
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets are amortized	9 years
Customer programs | Maximum
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets are amortized	20 years
Customer relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets are amortized	4 years
Customer relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets are amortized	10 years
Other | Minimum
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets are amortized	3 years
Other | Maximum
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets are amortized	10 years