v3.22.1
Income Taxes - Additional Information (Detail)
$ in Millions, ¥ in Billions
12 Months Ended
Dec. 31, 2021
CNY (¥)
Dec. 31, 2021
USD ($)
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2021
USD ($)
Income Taxes [Line Items]          
Unified statutory income tax rate under current EIT law 25.00% 25.00%      
PRC statutory withholding tax rate to which dividends paid by a FIE to any of its foreign non-resident enterprise investors 10.00% 10.00%      
PRC special withholding tax rate to which dividends paid by a FIE to its foreign non-resident enterprise investors in Hong Kong 5.00% 5.00%      
Statutory withholding tax rate for capital gains 10.00% 10.00%      
Net losses deriving from entities in the PRC, Hong Kong and Japan ¥ 16.6       $ 2,600
Accrued withholding tax 1.9 $ 284      
Undistributed earnings no withholding tax has accrued ¥ 165.5       $ 26,000
High And New Technology Enterprise          
Income Taxes [Line Items]          
A preferential enterprise income tax rate 15.00% 15.00%      
Net operating loss carryforward period 10 years 10 years      
PRC          
Income Taxes [Line Items]          
Net operating loss carryforward period 5 years 5 years      
Net operating loss carryforwards begins to expire 2022 2022      
Japan          
Income Taxes [Line Items]          
Net operating loss carryforward period 9 years 9 years      
Baidu HK          
Income Taxes [Line Items]          
Income tax rate 16.50% 16.50%      
Baidu Japan          
Income Taxes [Line Items]          
Income tax rate 31.00% 31.00% 31.00% 31.00%  
Certain PRC Subsidiaries and VIEs | High And New Technology Enterprise          
Income Taxes [Line Items]          
A preferential enterprise income tax rate 15.00% 15.00%      
Certain PRC Subsidiaries and VIEs | High And New Technology Enterprise | Expiration Period Two          
Income Taxes [Line Items]          
Tax holiday, expiration year 2022 2022      
Certain PRC Subsidiaries and VIEs | High And New Technology Enterprise | Expiration Period Three          
Income Taxes [Line Items]          
Tax holiday, expiration year 2023 2023