v2.4.1.9
EMPLOYEE BENEFIT PLAN (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
EMPLOYEE BENEFIT PLAN [Abstract]      
Multiemployer plans, employer contributions, percentage of employee salaries 5.00%acts_MultiemployerPlansEmployerContributionsPercentageOfEmployeeSalaries    
Multiemployer plan, period contributions $ 3,929us-gaap_MultiemployerPlanPeriodContributions $ 3,084us-gaap_MultiemployerPlanPeriodContributions $ 2,717us-gaap_MultiemployerPlanPeriodContributions