Fair Value Measurements - Fair Value of Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, at estimated fair value-warrants	$ 85	$ 322
Derivative instrument liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, at estimated fair value-warrants	85	322
Fair value on a recurring basis | Warrants | Derivative instrument liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, at estimated fair value-warrants	85	322
Fair value on a recurring basis | Warrants | Derivative instrument liability | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments, at estimated fair value-warrants	$ 85	$ 322