v3.25.3
Reportable Segments (Details)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2025
USD ($)
Sep. 30, 2024
USD ($)
Sep. 30, 2025
USD ($)
segments
Sep. 30, 2024
USD ($)
Dec. 31, 2024
USD ($)
Segment Reporting Information [Line Items]          
Number of reportable segments | segments     2    
Operating Revenues $ 540.9 $ 473.5 $ 1,693.5 $ 1,461.5  
Costs associated with service revenues 8.4 6.4 23.6 20.2  
Costs associated with product sales 101.9 62.7 320.4 205.4  
Operation and maintenance 79.7 78.2 212.9 216.2  
Administrative and general 50.4 45.6 145.2 137.8  
Taxes other than income taxes 32.6 30.2 98.2 90.6  
Loss (gain) on sale of assets, impairments and other 0.2 1.2 (0.7) (6.5)  
Miscellaneous other income, net 1.0 0.4 2.8 4.3  
Segment EBITDA 268.7 249.6 896.7 802.1  
Depreciation and amortization 106.2 105.7 330.6 317.7  
Interest expense 39.5 46.8 118.8 137.0  
Interest income (4.0) (9.7) (8.0) (22.2)  
Consolidated income before income taxes 127.0 106.8 455.3 369.6  
Total Assets 10,068.3   10,068.3   $ 9,779.4
Capital expenditures     222.4 291.9  
Operating Segments          
Segment Reporting Information [Line Items]          
Revenue From External Customers 540.9 473.5 1,693.5 1,461.5  
Intrasegment revenues 12.1 12.6 38.0 37.3  
Operating Revenues 553.0 486.1 1,731.5 1,498.8  
Total Assets 9,032.4   9,032.4   9,118.8
Intersegment Eliminations          
Segment Reporting Information [Line Items]          
Intrasegment revenues 12.1 12.6 38.0 37.3  
Operating Revenues (12.1) (12.6) (38.0) (37.3)  
Natural Gas Reportable Segment          
Segment Reporting Information [Line Items]          
Revenue From External Customers 358.7 320.6 1,131.8 1,011.9  
Natural Gas Reportable Segment | Operating Segments          
Segment Reporting Information [Line Items]          
Intrasegment revenues 12.1 12.6 38.0 37.3  
Operating Revenues 370.8 333.2 1,169.8 1,049.2  
Costs associated with service revenues 11.0 9.4 34.5 29.2  
Costs associated with product sales 0.0 0.0 0.0 0.0  
Operation and maintenance 67.8 64.6 178.4 173.5  
Administrative and general 46.9 43.6 137.4 131.7  
Taxes other than income taxes 29.4 26.7 88.6 80.3  
Loss (gain) on sale of assets, impairments and other 0.2 0.2 (0.7) (7.5)  
Miscellaneous other income, net (1.0) (0.4) (2.8) (4.2)  
Segment EBITDA 216.5 189.1 734.4 646.2  
Total Assets 7,540.5   7,540.5   7,490.1
Capital expenditures     198.7 252.3  
Natural Gas Liquids Reportable Segment          
Segment Reporting Information [Line Items]          
Revenue From External Customers 182.2 152.9 561.7 449.6  
Natural Gas Liquids Reportable Segment | Operating Segments          
Segment Reporting Information [Line Items]          
Operating Revenues 182.2 152.9 561.7 449.6  
Costs associated with service revenues 5.2 4.9 13.8 14.2  
Costs associated with product sales 101.9 62.7 320.4 205.4  
Operation and maintenance 11.9 13.6 34.5 42.7  
Administrative and general 7.8 6.7 21.1 20.2  
Taxes other than income taxes 3.2 3.5 9.6 10.3  
Loss (gain) on sale of assets, impairments and other 0.0 1.0 0.0 1.0  
Miscellaneous other income, net 0.0 0.0 0.0 (0.1)  
Segment EBITDA 52.2 $ 60.5 162.3 155.9  
Total Assets $ 1,491.9   1,491.9   $ 1,628.7
Capital expenditures     $ 23.7 $ 39.6