v3.20.4
UNIT-BASED COMPENSATION (Tables)
 12 Months Ended
Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Summary of long-term incentive plan compensation expense
The following table summarizes information pertaining to all of our long-term incentive plans:
Units Outstanding
December 31,		Compensation Expense
Year Ended December 31,
202020192018202020192018
(Thousands of Dollars)
Restricted units:
Domestic employees 2,235,125 1,223,143 1,028,484 $10,205 $9,437 $8,233 
Non-employee directors (NEDs)
98,769 61,349 59,752 631 774 524 
International employees19,987 10,243 30,918 58 711 1,158 
Performance awards87,122 161,561 158,326 1,291 4,172 1,889 
Unit awards— — — — 22,941 18,895 
Total 2,441,003 1,456,296 1,277,480 $12,185 $38,035 $30,699 
Restricted unit award activity
A summary of our equity-classified restricted unit awards is as follows:
Measured at Grant Date Fair ValueMeasured at Market Price
Number of UnitsWeighted-Average Fair Value Per UnitNumber of NEDs Units
Nonvested units as of January 1, 2018
736,746 $35.95 27,097 
Converted on July 20, 201853,447 24.99 18,915 
Granted518,282 24.07 34,303 
Vested(235,746)35.12 (20,563)
Forfeited(44,245)36.05 — 
Nonvested units as of December 31, 2018
1,028,484 29.47 59,752 
Change in measurement (a)59,752 20.93 (59,752)
Granted596,881 26.46 — 
Vested(328,386)30.11 — 
Forfeited(72,239)28.05 — 
Nonvested units as of December 31, 2019
1,284,492 27.48 — 
Granted1,454,998 12.10 — 
Vested(374,847)28.47 — 
Forfeited(30,749)26.75 — 
Nonvested units as of December 31, 2020
2,333,894 17.70 — 
(a) On January 1, 2019 we adopted amended guidance that allows for the fair value of these awards to be measured at the grant date. The unvested restricted units granted to NEDs as of January 1, 2019 were measured at the fair value as of that date.
Performance Units [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Summary of long-term incentive plan compensation expense
A summary of our performance unit awards is shown below:
Granted for Accounting Purposes
Total Performance
Unit Awards		Performance Unit AwardsWeighted-Average Grant Date Fair Value per Unit
Outstanding as of January 1, 2018
80,961 38,865 $50.04 
Granted116,230 80,690 23.43 
Forfeitures(38,865)(38,865)50.04 
Outstanding as of December 31, 2018
158,326 80,690 23.43 
Granted95,969 74,439 28.01 
Vested(80,690)(80,690)23.43 
Forfeitures(12,044)— — 
Outstanding as of December 31, 2019
161,561 74,439 28.01 
Granted— 57,448 13.21 
Performance adjustment (a)72,951 72,951 28.01 
Vested(147,390)(147,390)28.01 
Outstanding as of December 31, 2020
87,122 57,448 13.21 
(a) Common units granted and issued upon vesting of performance units earned at 198% of target related to the performance awards granted in 2019 and 2018.
Share-based Payment Arrangement [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Summary of long-term incentive plan compensation expense A summary of our unit awards is shown below:
Date of GrantGrant Date Fair ValueUnit Awards GrantedCommon Units Issued, Net of Employee Withholding Tax
(Thousands of Dollars)
February and March 2020$22,941 834,224 571,735 
February 2019$17,537 704,886 482,971 
July 2018$1,358 55,133 35,745