Segments - Financial Data for Each Reportable Segment (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Revenues and other income	$ 378.5	$ 363.1	$ 1,099.6	$ 992.1
Operating and maintenance expenses (exclusive of depreciation shown separately below)	89.0	89.4	254.6	225.0
Depreciation expense	51.5	47.7	151.8	142.1
General and administrative expenses	6.3	6.0	17.2	18.2
Income from equity investments	3.7	2.0	10.1	5.3
Interest expense, net	51.8	45.8	150.0	131.2
Income tax expense	18.9	11.4	49.2	26.0
Adjusted EBITDA	289.3	271.7	844.2	760.7
Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income	378.5	363.1	1,099.6	992.1
Operating and maintenance expenses (exclusive of depreciation shown separately below)	89.0	89.4	254.6	225.0
Depreciation expense	51.5	47.7	151.8	142.1
General and administrative expenses	3.9	4.0	10.9	11.7
Income from equity investments	3.7	2.0	10.1	5.3
Adjusted EBITDA	289.3	271.7	844.2	760.7
Capital expenditures	96.3	64.5	204.2	173.9
Interest and Other
Segment Reporting Information [Line Items]
General and administrative expenses	2.4	2.0	6.3	6.5
Interest expense, net	51.8	45.8	150.0	131.2
Income tax expense	18.9	11.4	49.2	26.0
Gathering Opco | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income	203.5	197.5	587.1	536.7
Operating and maintenance expenses (exclusive of depreciation shown separately below)	51.3	52.5	148.4	134.7
Depreciation expense	32.2	28.9	94.5	85.9
General and administrative expenses	2.4	2.5	6.8	7.4
Adjusted EBITDA	149.8	142.5	431.9	394.6
Capital expenditures	93.3	60.3	194.5	156.1
Processing and Storage | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income	145.1	133.2	423.7	370.4
Operating and maintenance expenses (exclusive of depreciation shown separately below)	30.3	26.7	82.8	70.7
Depreciation expense	15.0	14.5	44.3	43.5
General and administrative expenses	1.2	1.2	3.4	3.5
Income from equity investments	3.7	2.0	10.1	5.3
Adjusted EBITDA	117.3	107.3	347.6	301.5
Capital expenditures	3.0	4.2	9.6	7.8
Terminaling and Export | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income	29.9	32.4	88.8	85.0
Operating and maintenance expenses (exclusive of depreciation shown separately below)	7.4	10.2	23.4	19.6
Depreciation expense	4.3	4.3	13.0	12.7
General and administrative expenses	0.3	0.3	0.7	0.8
Adjusted EBITDA	$ 22.2	$ 21.9	64.7	64.6
Capital expenditures			$ 0.1	$ 10.0