Income Taxes - Narrative Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) state	Dec. 31, 2014 USD ($) state	Dec. 31, 2013 USD ($) state
Federal tax expense	$ 0	$ 0	$ 0
Number of states with state tax liability | state	1	1	1
Deferred federal income tax expense	$ 6	$ 0	$ 0
Deferred state income tax expense	1	$ 0	$ 0
U.S. Federal [Member]
Net operating loss carryforwards	167,200
State [Member]
Net operating loss carryforwards	$ 149,800