Changes in Capital Structure - NRG Common Stock Dividends (Details) - $ / shares |
3 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|
Apr. 17, 2024 |
Mar. 31, 2024 |
Mar. 31, 2023 |
Dec. 31, 2023 |
|
| Subsequent Event [Line Items] | ||||
| Common stock dividends proposed annual amount (in usd per share) | $ 1.51 | $ 1.63 | ||
| Dividends per common share (in usd per share) | $ 0.4075 | $ 0.3775 | ||
| Subsequent Event | ||||
| Subsequent Event [Line Items] | ||||
| Common stock dividends declared (in usd per share) | $ 0.4075 | |||
| Minimum | ||||
| Subsequent Event [Line Items] | ||||
| Common stock, annual dividend growth rate, percentage | 7.00% | |||
| Maximum | ||||
| Subsequent Event [Line Items] | ||||
| Common stock, annual dividend growth rate, percentage | 9.00% | |||