XML 14 R1.htm IDEA: XBRL DOCUMENT v3.25.3
Cover - shares
 9 Months Ended
Sep. 30, 2025
Nov. 12, 2025
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2025  
Document Transition Report false  
Entity File Number 001-35424  
Entity Registrant Name MECHANICS BANCORP  
Entity Incorporation, State or Country Code WA  
Entity Tax Identification Number 91-0186600  
Entity Address, Address Line One 1111 Civic Drive  
Entity Address, Address Line Two Suite 390  
Entity Address, City or Town Walnut Creek  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 94596  
City Area Code 925  
Local Phone Number 482-8000  
Title of 12(b) Security Class A, Common Stock  
Trading Symbol MCHB  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Accelerated Filer  
Smaller Reporting Company true  
Emerging Growth Company false  
Entity Shell Company false  
Entity Central Index Key 0001518715  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q3  
Amendment Flag false  
Common Class A    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding (in shares)   220,099,202
Common Class B    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding (in shares)   1,114,448