Commitments and Contingencies Liquidity Outlook (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Cash and Cash Equivalents, at Carrying Value	$ 46,248	$ 33,087	$ 30,926	$ 20,764