Investment in Common Stock of Ascendance Biotechnology, Inc. (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 09, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Gain on acquisition		$ 3,694	$ 0	$ 0
Ascendance Biotechnology, Inc [Member]
Business Acquisition [Line Items]
Acquired equity interest	51.20%
Fair value of investment	$ 4,700
Carrying amount of assets	1,000
Gain on acquisition	$ 3,700