v2.4.1.9
INVESTMENT IN EQUITY METHOD INVESTEES (Schedule of Carrying Value of Equity Method Investees) (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
May 31, 2014
Dec. 31, 2013
Apr. 30, 2013
Schedule of Equity Method Investments [Line Items]        
Carrying value of equity method investees $ 27,352us-gaap_EquityMethodInvestments   $ 17,843us-gaap_EquityMethodInvestments  
Beijing Actions [Member]        
Schedule of Equity Method Investments [Line Items]        
Carrying value of equity method investees 3,332us-gaap_EquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= acts_ActionsMicroelectronicsCoLtdMember
  2,856us-gaap_EquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= acts_ActionsMicroelectronicsCoLtdMember
 
Nann Capital [Member]        
Schedule of Equity Method Investments [Line Items]        
Carrying value of equity method investees $ 24,020us-gaap_EquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= acts_NannCapitalCorporationNannCapitalMember
$ 9,016us-gaap_EquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= acts_NannCapitalCorporationNannCapitalMember
$ 14,987us-gaap_EquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= acts_NannCapitalCorporationNannCapitalMember
$ 3,712us-gaap_EquityMethodInvestments
/ us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis
= acts_NannCapitalCorporationNannCapitalMember