v3.8.0.1
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2018
Apr. 20, 2018
Document and Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Fiscal Period Focus Q1  
Document Period End Date Mar. 31, 2018  
Document Fiscal Year Focus 2018  
Current Fiscal Year End Date --12-31  
Entity Registrant Name PICO HOLDINGS INC /NEW  
Entity Central Index Key 0000830122  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   22,520,153