Basis of Presentation and Summary of Significant Accounting Policies - Summary of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Cash and cash equivalents	$ 35,376	$ 24,082	$ 19,875
Restricted cash	10,130	8,094	9,037
Total cash, cash equivalents, and restricted cash	$ 45,506	$ 32,176	$ 28,912	$ 47,357