Employees, Retirement and Incentive Plans (Tables)

9 Months Ended

Sep. 30, 2020

Share-based Payment Arrangement [Abstract]

Schedule of Nonvested Restricted Stock Units Activity

A summary of restricted and phantom unit activity and changes during the nine months ended September 30, 2020, is presented below:

Restricted and Phantom Units	Units	Weighted Average Grant-Date Fair Value
Outstanding at January 1, 2020 (nonvested)	145,205	$	26.22
Vesting and transfer of full ownership to recipients	(5,646)	29.94
Forfeited	(8,578)	25.47
Outstanding at September 30, 2020 (nonvested)	130,981	$	26.11

Schedule of Nonvested Performance-based Units Activity

A summary of performance unit activity and changes for the nine months ended September 30, 2020, is presented below:

Performance Units	Units
Outstanding at January 1, 2020 (nonvested)	53,445
Vesting and transfer of common units to recipients	(11,634)
Outstanding at September 30, 2020 (nonvested)	41,811