v3.22.1
Organization and Basis of Presentation - Additional Information (Detail)
$ / shares in Units, ¥ in Billions
 12 Months Ended
Dec. 31, 2021
CNY (¥)
shares
Dec. 31, 2021
USD ($)
$ / shares
shares
Mar. 01, 2021
$ / shares
Dec. 31, 2020
$ / shares
shares
Organization [Line Items]        
Total authorized share capital | $   $ 43,520    
Stock holders equity note stock split each ADS now represents eight Class A ordinary shares      
Class A Ordinary Shares        
Organization [Line Items]        
Common stock, par value per share | $ / shares   $ 0.000000625   $ 0.000000625
Common stock, shares authorized | shares 66,000,000,000 66,000,000,000   66,000,000,000
Class A Ordinary Shares | Previously Reported        
Organization [Line Items]        
Common stock, par value per share | $ / shares       $ 0.00005
Common stock, shares authorized | shares       825,000,000
Class B Ordinary Shares        
Organization [Line Items]        
Common stock, par value per share | $ / shares   $ 0.000000625   $ 0.000000625
Common stock, shares authorized | shares 2,832,000,000 2,832,000,000   2,832,000,000
Class B Ordinary Shares | Previously Reported        
Organization [Line Items]        
Common stock, par value per share | $ / shares       $ 0.00005
Common stock, shares authorized | shares 35,400,000 35,400,000    
Preferred Stock        
Organization [Line Items]        
Preferred Stock , par value per share | $ / shares   $ 0.000000625 $ 0.000000625  
Preferred stock, shares authorized | shares 800,000,000 800,000,000    
Preferred Stock | Previously Reported        
Organization [Line Items]        
Preferred Stock , par value per share | $ / shares       $ 0.00005
Preferred stock, shares authorized | shares 10,000,000 10,000,000    
Variable Interest Entity, Primary Beneficiary [Member]        
Organization [Line Items]        
Net assets of VIEs ¥ 20.0 $ 3,100,000,000    
Beijing Perusal        
Organization [Line Items]        
Interest-free loans provided by a subsidiary of the entity to the shareholders of its variable interest entities ¥ 3.2 502,000,000    
Equity pledge agreement expiration period 2 years      
Baidu Netcom        
Organization [Line Items]        
Interest-free loans provided by a subsidiary of the entity to the shareholders of its variable interest entities ¥ 13.4 $ 2,100,000,000