XML 22 R32.htm IDEA: XBRL DOCUMENT v3.19.3
Related Party Transactions - Additional Information (Detail) - USD ($)
1 Months Ended 3 Months Ended 9 Months Ended
Aug. 31, 2016
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Oct. 01, 2019
Dec. 31, 2018
Related Party Transaction [Line Items]              
Note receivable from affiliate   $ 36,700,000   $ 36,700,000     $ 34,000,000
Unsecured Revolving Demand Promissory | Valhi Inc              
Related Party Transaction [Line Items]              
Maximum loan amount $ 40,000,000            
Interest rate on loans repayment 1.00% 6.00%   6.00%      
Principal due on demand effective date Dec. 31, 2020            
Note receivable from affiliate   $ 36,700,000   $ 36,700,000      
Interest income including unused commitment fees on our loan   600,000 $ 500,000 1,900,000 $ 1,600,000    
Amount loaned   $ 3,300,000   $ 3,300,000      
Unsecured Revolving Demand Promissory | Valhi Inc | Subsequent Event              
Related Party Transaction [Line Items]              
Note receivable from affiliate           $ 40,000,000