CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Restricted cash	$ 21,066	$ 11,789	$ 5,683	$ 6,192
Variable Interest Entity, Primary Beneficiary [Member]
Cash	24,348	20,685	15,461	30,449
Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Cash	$ 16,462	$ 14,735	$ 10,034	$ 15,685