Revenue from contracts with customers - Narrative (Details) $ in Millions	Mar. 31, 2025 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, amount	$ 587.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, amount	$ 82.6
Revenue, remaining performance obligation, expected timing of satisfaction, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, amount	$ 81.9
Revenue, remaining performance obligation, expected timing of satisfaction, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, amount	$ 423.2
Revenue, remaining performance obligation, expected timing of satisfaction, period
Pipeline
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract with customer, term (less than)	12 months
Pipeline | Firm Transportation Contract
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract weighted average remaining duration (less than)	5 years
Pipeline | Firm Storage Contract
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract weighted average remaining duration (less than)	2 years