Significant Accounting Policies - Reconciliation of Warrant Liability (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of warrant liability
Fair value of shareholder notes payable	$ 7,500	$ 7,700
Prior Period Adjustment
Prepaid expenses and other current assets	1,568	1,448
Income taxes payable	534	777
Reclassification
Prior Period Adjustment
Prepaid expenses and other current assets		(700)
Income taxes payable		700
Warrants
Reconciliation of warrant liability
Balance at beginning of period	1,474	939
Issuance of common stock warrants	4,215	2,978
Exercise of common stock warrants		(2,949)
Remeasurement of common stock warrants	(2,617)	506
Balance at end of period	$ 3,072	$ 1,474