SIGNIFICANT ACCOUNTING POLICIES Restricted Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Cash and cash equivalents	$ 25,813	$ 18,215
Restricted cash and cash equivalents	742,093	685,016
Total cash, cash equivalents and restricted cash presented in the consolidated statements of cash flows	$ 767,906	$ 703,231	$ 1,531,098	$ 1,242,509