Business and Organization (Details)	12 Months Ended
Dec. 31, 2020
Installation of systems in newly constructed facilities
Business and Organization
Percentage of revenue attributable to services	46.70%
Maintenance, repair and replacement services
Business and Organization
Percentage of revenue attributable to services	53.30%

The percentage of net services revenue to total net revenue from the services rendered as of the year end.

No definition available.

Name:	fix_SalesRevenueServicesNetPercentage
Namespace Prefix:	fix_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration