ACCOUNTING POLICIES - Schedule of VIEs (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Variable Interest Entity
Assets	$ 25,044,424	$ 23,929,404
Liabilities	13,596,935	13,415,723
Variable Interest Entity | NHP/PMB L.P.
Variable Interest Entity
Assets	750,455	649,128
Liabilities	253,675	238,168
Variable Interest Entity | Other Identified VIEs
Variable Interest Entity
Assets	4,016,054	4,095,102
Liabilities	1,673,060	1,653,036
Variable Interest Entity | Tax Credit VIEs
Variable Interest Entity
Assets	461,065	614,490
Liabilities	$ 105,525	$ 204,746