v2.4.1.9
Fair Value Measurements - Summary of the financial instruments of the company at fair value (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Carrying value $ 24,871us-gaap_CashCashEquivalentsAndShortTermInvestments $ 24,873us-gaap_CashCashEquivalentsAndShortTermInvestments
Money Market Funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Carrying value 331us-gaap_CashCashEquivalentsAndShortTermInvestments
/ us-gaap_CashAndCashEquivalentsAxis
= us-gaap_MoneyMarketFundsMember
365us-gaap_CashCashEquivalentsAndShortTermInvestments
/ us-gaap_CashAndCashEquivalentsAxis
= us-gaap_MoneyMarketFundsMember
Certificates of Deposit [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Carrying value   240us-gaap_CashCashEquivalentsAndShortTermInvestments
/ us-gaap_CashAndCashEquivalentsAxis
= us-gaap_CertificatesOfDepositMember
Fair Value, Inputs, Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value 331us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
365us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value 331us-gaap_AssetsFairValueDisclosure
/ us-gaap_CashAndCashEquivalentsAxis
= us-gaap_MoneyMarketFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
365us-gaap_AssetsFairValueDisclosure
/ us-gaap_CashAndCashEquivalentsAxis
= us-gaap_MoneyMarketFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
Fair Value, Inputs, Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value 24,531us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
24,479us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_CashAndCashEquivalentsAxis
= us-gaap_MoneyMarketFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
0us-gaap_AssetsFairValueDisclosure
/ us-gaap_CashAndCashEquivalentsAxis
= us-gaap_MoneyMarketFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Fair Value, Inputs, Level 2 [Member] | Certificates of Deposit [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value   240us-gaap_AssetsFairValueDisclosure
/ us-gaap_CashAndCashEquivalentsAxis
= us-gaap_CertificatesOfDepositMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
Fair Value, Inputs, Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_CashAndCashEquivalentsAxis
= us-gaap_MoneyMarketFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
0us-gaap_AssetsFairValueDisclosure
/ us-gaap_CashAndCashEquivalentsAxis
= us-gaap_MoneyMarketFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
Corporate Bond Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Carrying value 3,020us-gaap_CashCashEquivalentsAndShortTermInvestments
/ us-gaap_InvestmentTypeAxis
= us-gaap_CorporateBondSecuritiesMember
3,033us-gaap_CashCashEquivalentsAndShortTermInvestments
/ us-gaap_InvestmentTypeAxis
= us-gaap_CorporateBondSecuritiesMember
Corporate Bond Securities [Member] | Fair Value, Inputs, Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_InvestmentTypeAxis
= us-gaap_CorporateBondSecuritiesMember
0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_InvestmentTypeAxis
= us-gaap_CorporateBondSecuritiesMember
Corporate Bond Securities [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value 3,017us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_InvestmentTypeAxis
= us-gaap_CorporateBondSecuritiesMember
3,028us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_InvestmentTypeAxis
= us-gaap_CorporateBondSecuritiesMember
Corporate Bond Securities [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_InvestmentTypeAxis
= us-gaap_CorporateBondSecuritiesMember
0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_InvestmentTypeAxis
= us-gaap_CorporateBondSecuritiesMember
Certificates of Deposit [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Carrying value 21,520us-gaap_CashCashEquivalentsAndShortTermInvestments
/ us-gaap_InvestmentTypeAxis
= us-gaap_CertificatesOfDepositMember
21,235us-gaap_CashCashEquivalentsAndShortTermInvestments
/ us-gaap_InvestmentTypeAxis
= us-gaap_CertificatesOfDepositMember
Certificates of Deposit [Member] | Fair Value, Inputs, Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_InvestmentTypeAxis
= us-gaap_CertificatesOfDepositMember
0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
/ us-gaap_InvestmentTypeAxis
= us-gaap_CertificatesOfDepositMember
Certificates of Deposit [Member] | Fair Value, Inputs, Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value 21,514us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_InvestmentTypeAxis
= us-gaap_CertificatesOfDepositMember
21,211us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member
/ us-gaap_InvestmentTypeAxis
= us-gaap_CertificatesOfDepositMember
Certificates of Deposit [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair market value $ 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_InvestmentTypeAxis
= us-gaap_CertificatesOfDepositMember
$ 0us-gaap_AssetsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel3Member
/ us-gaap_InvestmentTypeAxis
= us-gaap_CertificatesOfDepositMember