XML 74 R61.htm IDEA: XBRL DOCUMENT v3.21.2
Segment Information - Narrative (Details)
9 Months Ended
Sep. 30, 2021
segment
Segment Reporting Information [Line Items]  
Number of reportable segments 3
Osage Pipeline  
Segment Reporting Information [Line Items]  
Equity method investment, ownership percentage 50.00%
UNEV Pipeline  
Segment Reporting Information [Line Items]  
Equity method investment, ownership percentage 75.00%