INVESTMENTS AVAILABLE FOR SALE AND HELD TO MATURITY (Details) $ in Thousands	Mar. 31, 2016 USD ($)
Available-for-sale, Amortized Cost
Within 1 year	$ 255,325
After 1 year through 5 years	260,572
Total	515,897
Available-for-sale, Estimated Fair Value
Within 1 year	255,260
After 1 year through 5 years	260,762
Total	516,022
Held-to-maturity, Amortized Cost
Within 1 year	1,715
After 1 year through 5 years	1,667
Total	3,382
Held-to-maturity, Estimated Fair Value
Within 1 year	1,715
After 1 year through 5 years	1,667
Estimated Fair Value	$ 3,382