Fair Value Measurements - Fair Value of Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities related to Warrants	$ 94	$ 216
Derivative instrument liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities related to Warrants	94	216
Fair value on a recurring basis | Warrants | Derivative instrument liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities related to Warrants	94	216
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 liabilities related to Warrants	$ 94	$ 216