INVESTMENTS - REALIZED GAINS AND LOSSES (Details) - USD ($) $ in Thousands |
9 Months Ended | |
|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| INVESTMENTS | ||
| Proceeds from the sales and maturities of marketable securities | $ 493,520 | $ 335,169 |
| Realized gains | 124 | 109 |
| Realized losses | $ 28 | $ 3 |