Business and Organization (Details)	12 Months Ended
	Dec. 31, 2012
Installation of systems in newly constructed facilities
Business and Organization
Percentage of revenue attributable to services	47.00%
Maintenance, repair and replacement service
Business and Organization
Percentage of revenue attributable to services	53.00%
HVAC
Business and Organization
Percentage of revenue attributable to services	75.00%
Plumbing
Business and Organization
Percentage of revenue attributable to services	16.00%
Building automation control systems
Business and Organization
Percentage of revenue attributable to services	5.00%
Other
Business and Organization
Percentage of revenue attributable to services	4.00%