Fair Value of Financial Instruments - Fair Value, Financial Assets, Recurring (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Promissory note		$ 4,946
Total assets at fair value	$ 5,007	9,946
Fair Value, Inputs, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets at fair value	5,007	5,000
Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Promissory note		4,946
Total assets at fair value		4,946
Money Market Funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	5,007	5,000
Money Market Funds | Fair Value, Inputs, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 5,007	$ 5,000