STOCK-BASED COMPENSATION (Tables)
|3 Months Ended|
Mar. 31, 2019
|Disclosure of Compensation Related Costs, Share-based Payments [Abstract]|
|Fair Value of Employee Stock Options Granted and Determined by Black-Scholes Valuation Model Assumptions||The fair value of each option grant is estimated using the Black-Scholes option pricing model. The weighted-average assumptions used and the calculated weighted-average fair values of options granted in 2019 and 2018 are as follows:
The weighted-average assumptions used and the calculated weighted-average fair values of the RTSR portion of the LTIP awards granted in 2019 and 2018 are as follows:
Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions.
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef