DERIVATIVE INSTRUMENTS - Risks (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |
|---|---|---|---|
Sep. 30, 2022 |
Sep. 30, 2022 |
Mar. 31, 2022 |
|
| Concentration Risk [Line Items] | |||
| Percentage change in interest rates | 1.00% | ||
| Effect on net loss from change in interest rates | $ 0.3 | ||
| Percentage increase in price | 10.00% | ||
| Percentage decrease in price | 10.00% | ||
| Increase (decrease) in income from increase in price | $ 419.7 | $ 419.7 | |
| Increase (decrease) in income from decrease in price | 418.1 | 418.1 | |
| Adjustment factor | 2.1 | 2.1 | $ 2.3 |
| Counterparty credit risk exposure | 424.2 | 424.2 | 580.5 |
| Cash Collateral from Counterparties | 56.9 | 56.9 | 103.2 |
| Counterparty Credit Risk Exposure, Net Amount | 367.3 | 367.3 | 477.3 |
| Cash collateral posted | $ 4.9 | $ 4.9 | $ 20.3 |
| Maximum | |||
| Concentration Risk [Line Items] | |||
| Current cash flows, percentage hedged | 100.00% | ||
| Noncurrent cash flows, percentage hedged | 50.00% | ||
| Minimum | |||
| Concentration Risk [Line Items] | |||
| Current cash flows, percentage hedged | 50.00% | ||
| Noncurrent cash flows, percentage hedged | 0.00% |