Basis of Presentation - Summary of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Cash and Cash Equivalents	$ 24,924	$ 18,026	$ 38,859	$ 57,421
Restricted Cash	0	37,505	0	0
Cash, Cash Equivalents, and Restricted Cash	$ 24,924	$ 55,531	$ 38,859	$ 57,421