Annual report pursuant to Section 13 and 15(d)

FAIR VALUE MEASUREMENTS - Assets Measured at Fair Value on a Nonrecurring Basis (Details)

v3.10.0.1
FAIR VALUE MEASUREMENTS - Assets Measured at Fair Value on a Nonrecurring Basis (Details) - USD ($)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Total gains (losses) $ 0 $ 0 $ (6,305,000)
Total gains (losses) $ 0 $ 0 $ (1,177,000)