INVESTMENTS - Net Gains from Investment Activities (Detail) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Equity Method Investments and Joint Ventures [Abstract]        
Realized gains (losses) on sales of investments $ 472 $ 33 $ 375 $ 187
Net change in unrealized gains (losses) due to changes in fair value(1) 17,274 80,917 49,912 107,305
Net gains (losses) from investment activities $ 17,746 $ 80,950 $ 50,287 $ 107,492