Business segment information - Holding Percentage of Subsidiaries (Details)	Mar. 31, 2025
Chemicals
Business segment information
Controlling interest in subsidiary	81.00%
Component products
Business segment information
Controlling interest in subsidiary	87.00%
Real estate management and development | Basic Management Inc
Business segment information
Controlling interest in subsidiary	63.00%
Real estate management and development | LandWell | Aggregate General And Limited Interests
Business segment information
Controlling interest in subsidiary	77.00%