STOCKHOLDERS' EQUITY AND EARNINGS PER SHARE (Details 5) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Unrealized (losses) gains on available-for-sale investment securities:
Net unrealized (losses) gains arising during the period, before-tax amount	$ 22,634	$ 2,698	$ 34,648	$ 54,933
Reclassification adjustment for gains included in net income, before-tax amount	(17,036)	(2,514)	(26,994)	(6,603)
Net change, before-tax amount	5,598	184	7,654	48,330
Foreign currency translation adjustments :
Net unrealized losses arising during the period, before-tax amount	(6,846)	0	(6,846)	0
Other comprehensive (loss) income, before-tax amount	(1,248)	184	808	48,330
Unrealized (losses) gains on available-for-sale investment securities:
Net unrealized (losses) gains arising during the period, tax expense or benefit	(9,507)	(1,133)	(14,552)	(23,072)
Reclassification adjustment for gains included in net income, tax expense or benefit	7,155	1,056	11,337	2,773
Net change, tax expense or benefit	(2,352)	(77)	(3,215)	(20,299)
Foreign currency translation adjustments :
Net unrealized losses arising during the period, tax expense or benefit	0	0	0	0
Other comprehensive (loss) income, tax expense or benefit	(2,352)	(77)	(3,215)	(20,299)
Unrealized (losses) gains on available-for-sale investment securities:
Net unrealized (losses) gains arising during the period, net-of-tax amount	13,127	1,565	20,096	31,861
Reclassification adjustment for gains included in net income, net-of-tax amount	9,881	1,458	15,657	3,830
Net change, net-of-tax amount	3,246	107	4,439	28,031
Foreign currency translation adjustments :
Net unrealized losses arising during the period, net-of-tax amount	(6,846)	0	(6,846)	0
Other comprehensive (loss) income	$ (3,600)	$ 107	$ (2,407)	$ 28,031