Variable Interest Entity Arrangements (Details) - USD ($)	1 Months Ended		6 Months Ended
	Jul. 31, 2021	Apr. 30, 2021	Jun. 30, 2021	Apr. 03, 2018
Variable Interest Entity [Line Items]
Liquidation IRR Hurdle			7.00%
Variable Interest Investment				$ 300,000,000.0
Methodology for Determining Whether Entity is Primary Beneficiary			The two variable interests applicable to Unit include the 50% equity investment in Superior and the MSA. The MSA gives us the power to direct the activities that most significantly affect Superior's operating performance. The MSA is a separate variable interest. Under the MSA, Unit has the power to direct Superior’s most significant activities; reciprocally the equity investors lack the power to direct the activities that most affect the entity’s economic performance. Because of this, Unit is considered the primary beneficiary.
Distributions paid		$ 24,700,000
Subsequent Event [Member]
Variable Interest Entity [Line Items]
Distributions paid	$ 7,700,000
VIE
Variable Interest Entity [Line Items]
Date Involvement Began			Apr. 03, 2018
SPC Midstream Operating, L.L.C. [Member] | VIE
Variable Interest Entity [Line Items]
Monthly service fee			$ 263,280
SP Investor Holdings, LLC [Member] | VIE
Variable Interest Entity [Line Items]
Ownership Percentage			50.00%