DISCLOSURES REGARDING FAIR VALUES OF FINANCIAL INSTRUMENTS - Securities in Unrealized Loss Position (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Securities in an unrealized loss position, fair value [Abstract]
One year or greater	$ 572,216	$ 706,839
Less than one year	933,211	1,095,724
Fair Value, Total	1,505,427	1,802,563
Securities in an unrealized loss position, aggregate loss [Abstract]
One year or greater	3,054	5,320
Less than one year	2,358	2,055
Unrealized Losses, Total	$ 5,412	$ 7,375