Fair Value Measurements (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Warrants Not Settleable in Cash, Fair Value Disclosure		$ 4,914
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Warrants, Acquired From Acquisition		4,914	$ 5,552
Gain on Sale of Investments	$ 1,402	530
Proceeds from Issuance of Warrants	(1,894)	(1,529)
Stock and Warrants Issued During Period, Value, Preferred Stock and Warrants	1,911	363
Equity Warrants Transfers to Available For Sale Securities	$ (836)	(2)
Warrants Not Settleable in Cash, Fair Value Disclosure		$ 4,914