XML 111 R58.htm IDEA: XBRL DOCUMENT v3.8.0.1
Equity and Stock-based Compensation - Subsidiary Stock and Non-Controlling Interests - Additional information (Detail) - $ / shares
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Nov. 19, 2014
Class Of Stock [Line Items]      
Preferred stock, shares outstanding 0 0  
IPO [Member]      
Class Of Stock [Line Items]      
Conversion rights, shares issued upon conversion of each preferred share     958,996
FibroGen Europe [Member]      
Class Of Stock [Line Items]      
Preferred stock, shares outstanding 42,619,022 42,619,022  
Preferred stock redemption percentage If a Preferred Share can be redeemed by a majority shareholder owning more than ninety percent (90%) of the shares of FibroGen Europe in accordance with the provisions of the Finnish Limited Liability Companies Act, the minority holders of Preferred Shares have the right to request redemption of their shares.    
Minimum percentage of shareholder's approval to call for redemption of preferred shares 90.00%    
Preferred stock, voting rights one vote    
Conversion rights, shares issued upon conversion of each preferred share 1    
FibroGen Europe [Member] | Series A [Member]      
Class Of Stock [Line Items]      
Preferred stock, shares outstanding 1,700,845 1,700,845  
FibroGen Europe [Member] | Series B [Member]      
Class Of Stock [Line Items]      
Preferred stock, shares outstanding 1,875,000 1,875,000  
FibroGen Europe [Member] | Series C [Member]      
Class Of Stock [Line Items]      
Preferred stock, shares outstanding 1,599,503 1,599,503  
FibroGen Europe [Member] | Series D [Member]      
Class Of Stock [Line Items]      
Preferred stock, shares outstanding 1,520,141 1,520,141  
FibroGen Europe [Member] | Series E [Member]      
Class Of Stock [Line Items]      
Preferred stock, shares outstanding 459,565 459,565  
FibroGen Europe [Member] | Series F [Member]      
Class Of Stock [Line Items]      
Preferred stock, shares outstanding 5,714,332 5,714,332  
FibroGen Europe [Member] | Series G [Member]      
Class Of Stock [Line Items]      
Preferred stock, shares outstanding 9,927,500 9,927,500  
FibroGen Europe [Member] | Series H [Member]      
Class Of Stock [Line Items]      
Preferred stock, shares outstanding 19,822,136 19,822,136  
FibroGen China [Member]      
Class Of Stock [Line Items]      
Conversion rights, shares issued upon conversion of each preferred share 1    
FibroGen China [Member] | Series A [Member]      
Class Of Stock [Line Items]      
Preferred stock, shares outstanding 6,758,000 6,758,000  
Preferred shares issued, price per share $ 1.00    
Cash dividend percentage 6.00%