ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			$ 3,122,950	$ 2,856,111
Other comprehensive income (loss)	$ 346	$ (8,125)	13,229	1,193
Ending balance	3,296,910	3,004,948	3,296,910	3,004,948
Available-for-Sale Investment Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	6,772	13,555	(6,144)	4,237
Net unrealized gains (losses) arising during the period	6,628	(4,904)	21,770	6,969
Amounts reclassified from AOCI	(1,644)	(3,221)	(3,870)	(5,776)
Other comprehensive income (loss)	4,984	(8,125)	17,900	1,193
Ending balance	11,756	5,430	11,756	5,430
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(8,830)		(8,797)
Net unrealized gains (losses) arising during the period	(4,638)	0	(4,671)	0
Amounts reclassified from AOCI	0		0
Other comprehensive income (loss)	(4,638)	0	(4,671)	0
Ending balance	(13,468)		(13,468)
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2,058)	13,555	(14,941)	4,237
Net unrealized gains (losses) arising during the period	1,990	(4,904)	17,099	6,969
Amounts reclassified from AOCI	(1,644)	(3,221)	(3,870)	(5,776)
Other comprehensive income (loss)	346	(8,125)	13,229	1,193
Ending balance	$ (1,712)	$ 5,430	$ (1,712)	$ 5,430