Segments - Financial Data for Each Reportable Segment (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Revenues and other income	$ 365.5	$ 324.0	$ 721.1	$ 629.0
Operating and maintenance expenses (exclusive of depreciation shown separately below)	87.5	73.1	165.6	135.6
Depreciation expense	50.5	47.0	100.3	94.4
General and administrative expenses	5.2	5.8	10.9	12.2
Income from equity investments	3.7	1.7	6.4	3.3
Interest expense, net	49.7	43.8	98.2	85.4
Income tax expense	16.0	8.1	30.3	14.6
Adjusted EBITDA	278.2	248.8	554.9	489.0
Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income	365.5	324.0	721.1	629.0
Operating and maintenance expenses (exclusive of depreciation shown separately below)	87.5	73.1	165.6	135.6
Depreciation expense	50.5	47.0	100.3	94.4
General and administrative expenses	3.5	3.8	7.0	7.7
Income from equity investments	3.7	1.7	6.4	3.3
Adjusted EBITDA	278.2	248.8	554.9	489.0
Capital expenditures	72.7	52.1	107.9	109.4
Interest and Other
Segment Reporting Information [Line Items]
General and administrative expenses	1.7	2.0	3.9	4.5
Interest expense, net	49.7	43.8	98.2	85.4
Income tax expense	16.0	8.1	30.3	14.6
Gathering Opco | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income	195.5	174.5	383.6	339.2
Operating and maintenance expenses (exclusive of depreciation shown separately below)	50.8	43.8	97.1	82.2
Depreciation expense	31.5	28.2	62.3	57.0
General and administrative expenses	2.3	2.5	4.4	4.9
Adjusted EBITDA	142.4	128.2	282.1	252.1
Capital expenditures	69.5	46.4	101.2	95.8
Processing and Storage | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income	139.5	122.8	278.6	237.2
Operating and maintenance expenses (exclusive of depreciation shown separately below)	27.3	23.8	52.5	44.0
Depreciation expense	14.6	14.5	29.3	29.0
General and administrative expenses	1.0	1.1	2.2	2.3
Income from equity investments	3.7	1.7	6.4	3.3
Adjusted EBITDA	114.9	99.6	230.3	194.2
Capital expenditures	3.2	2.7	6.6	3.6
Terminaling and Export | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income	30.5	26.7	58.9	52.6
Operating and maintenance expenses (exclusive of depreciation shown separately below)	9.4	5.5	16.0	9.4
Depreciation expense	4.4	4.3	8.7	8.4
General and administrative expenses	0.2	0.2	0.4	0.5
Adjusted EBITDA	$ 20.9	21.0	42.5	42.7
Capital expenditures		$ 3.0	$ 0.1	$ 10.0