ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 3,122,950	$ 2,856,111	$ 2,366,373
Other comprehensive (loss) income	(33,205)	(19,178)	34,696
Ending balance	3,427,741	3,122,950	2,856,111
Available- for-Sale Investment Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(6,144)	4,237	(30,459)
Net unrealized (losses) gains arising during the period	(16,623)	13,012	40,911
Amount reclassified from AOCI	(6,005)	(23,393)	(6,215)
Other comprehensive (loss) income	(22,628)	(10,381)	34,696
Ending balance	(28,772)	(6,144)	4,237
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(8,797)	0
Net unrealized (losses) gains arising during the period	(10,577)	(8,797)	0
Amount reclassified from AOCI	0	0
Other comprehensive (loss) income	(10,577)	(8,797)	0
Ending balance	(19,374)	(8,797)	0
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(14,941)	4,237	(30,459)
Net unrealized (losses) gains arising during the period	(27,200)	4,215	40,911
Amount reclassified from AOCI	(6,005)	(23,393)	(6,215)
Other comprehensive (loss) income	(33,205)	(19,178)	34,696
Ending balance	$ (48,146)	$ (14,941)	$ 4,237