Organization and Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Cash and cash equivalents	$ 40,867	$ 74,120
Restricted cash	46,333	24,769
Total cash, cash equivalents, and restricted cash shown on consolidated statement of cash flows	$ 87,200	$ 98,889	$ 85,125	$ 86,207