ACCOUNTING POLICIES - Schedule of VIEs (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Variable Interest Entity
Assets	$ 24,589,388	$ 24,692,208
Liabilities	13,957,558	13,873,078
Variable Interest Entity | NHP/PMB L.P.
Variable Interest Entity
Assets	656,814	666,404
Liabilities	238,045	244,934
Variable Interest Entity | Other Identified VIEs
Variable Interest Entity
Assets	3,878,671	4,075,821
Liabilities	1,498,774	1,459,830
Variable Interest Entity | Tax Credit VIEs
Variable Interest Entity
Assets	914,968	845,229
Liabilities	$ 352,945	$ 333,809