Distributions and Net Income Per Limited Partner Unit (Tables)

6 Months Ended

Jun. 30, 2019

Earnings Per Share [Abstract]

Distributions Made to Limited Partner, by Distribution [Table Text Block]

If cash distributions to the Partnership's unitholders exceed $1.2938 per unit in any quarter, the Partnership's unitholders and Westlake, as the holder of the Partnership's incentive distribution rights, will receive distributions according to the following percentage allocations:

	Marginal Percentage Interest in Distributions
Total Quarterly Distribution Per Unit	Unitholders		IDR Holders
Above $1.2938 up to $1.4063	85.0	%	15.0	%
Above $1.4063 up to $1.6875	75.0	%	25.0	%
Above $1.6875	50.0	%	50.0	%

The Partnership's distribution for the three months ended June 30, 2019 did not exceed the $1.2938 per unit threshold, and, as a result, no distribution was made with respect to the Partnership's incentive distribution rights to Westlake, as the holder of the Partnership's incentive distribution rights.

Distribution Per Common Unit

Distributions per common unit for the three and six months ended June 30, 2019 and 2018 were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2019		2018		2019		2018
Distributions per common unit	$	0.4452	$	0.3975	$	0.8780	$	0.7839

Schedule of Incentive Distributions Made to Managing Members or General Partners by Distribution

The distributions are declared subsequent to quarter end; therefore, the table below represents total distributions declared from earnings of the related periods pertaining to such distributions.

	Three Months Ended June 30,						Six Months Ended June 30,
	2019			2018			2019			2018
Net income attributable to the Partnership	$	13,733		$	12,757		$	28,688		$	25,052
Less:
Limited partners' distributions declared on common units	16,113			13,179			31,779			25,993
Distributions declared with respect to the incentive distribution rights	—			—			—			733
Distribution in excess of net income	$	(2,380	)	$	(422	)	$	(3,091	)	$	(1,674	)

Schedule of Earnings Per Share, Basic and Diluted

Net income per unit applicable to common limited partner units is computed by dividing the respective limited partners' interest in net income by the weighted-average number of common units outstanding for the period. Because the Partnership has more than one class of participating securities, it uses the two-class method when calculating the net income per unit applicable to limited partners. The classes of participating securities include common units and incentive distribution rights. Net income attributable to the Partnership is allocated to the unitholders in accordance with their respective ownership percentages in preparation of the consolidated statement of equity. However, when distributions related to the incentive distribution rights are made, net income equal to the amount of those distributions is first allocated to the general partner before the remaining net income is allocated to the unitholders based on their respective ownership percentages. Basic and diluted net income per unit is the same because the Partnership does not have any potentially dilutive units outstanding for the periods presented.

	Three Months Ended June 30, 2019
	Limited Partners' Common Units			Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution declared	$	16,113		$	—	$	16,113
Distribution in excess of net income	(2,380		)	—		(2,380		)
Net income	$	13,733		$	—	$	13,733
Weighted average units outstanding:
Basic and diluted	35,188,189					35,188,189
Net income per limited partner unit:
Basic and diluted	$	0.39

	Three Months Ended June 30, 2018
	Limited Partners' Common Units			Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution declared	$	13,179		$	—	$	13,179
Distribution in excess of net income	(422		)	—		(422		)
Net income	$	12,757		$	—	$	12,757
Weighted average units outstanding:
Basic and diluted	32,237,266					32,237,266
Net income per limited partner unit:
Basic and diluted	$	0.40

	Six Months Ended June 30, 2019
	Limited Partners' Common Units			Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution declared	$	31,779		$	—	$	31,779
Distribution in excess of net income	(3,091		)	—		(3,091		)
Net income	$	28,688		$	—	$	28,688
Weighted average units outstanding:
Basic and diluted	33,774,647					33,774,647
Net income per limited partner unit:
Basic and diluted	$	0.85

	Six Months Ended June 30, 2018
	Limited Partners' Common Units			Incentive Distribution Rights		Total
Net income attributable to the Partnership:
Distribution declared	$	25,993		$	733	$	26,726
Distribution in excess of net income	(1,674		)	—		(1,674		)
Net income	$	24,319		$	733	$	25,052
Weighted average units outstanding:
Basic and diluted	32,236,860					32,236,860
Net income per limited partner unit:
Basic and diluted	$	0.75