Fixed Assets - Additional Information (Detail) - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Depreciation expense relating to fixed assets	$ 1.6	$ 2.0	$ 2.1
Building and Building Improvements | Minimum
Property Plant And Equipment [Line Items]
Useful Life	25 years
Building and Building Improvements | Maximum
Property Plant And Equipment [Line Items]
Useful Life	30 years
Machinery and Equipment | Minimum
Property Plant And Equipment [Line Items]
Useful Life	5 years
Machinery and Equipment | Maximum
Property Plant And Equipment [Line Items]
Useful Life	10 years