Long-Term Debt - Retired Through Optional Redemptions or Payments at Maturities (Details)
$ in Millions |
12 Months Ended |
|
Dec. 31, 2019
USD ($)
|
|---|
| Debt Instrument [Line Items] |
|
| Interest rate |
2.45%
|
| Debt retired during the year |
|
| Debt Instrument [Line Items] |
|
| Total retirements and redemptions |
$ 495
|
| Debt retired during the year | Other American Water subsidiaries | Mandatorily redeemable preferred stock |
|
| Debt Instrument [Line Items] |
|
| Total retirements and redemptions |
$ 2
|
| Debt retired during the year | Other American Water subsidiaries | Term loan |
|
| Debt Instrument [Line Items] |
|
| Maturity date, maximum |
2021
|
| Total retirements and redemptions |
$ 6
|
| Debt retired during the year | American Water Capital Corp. | Senior notes |
|
| Debt Instrument [Line Items] |
|
| Total retirements and redemptions |
$ 101
|
| Debt retired during the year | Minimum | Other American Water subsidiaries | Mandatorily redeemable preferred stock |
|
| Debt Instrument [Line Items] |
|
| Interest rate |
8.49%
|
| Maturity date, minimum |
2031
|
| Debt retired during the year | Minimum | Other American Water subsidiaries | Term loan |
|
| Debt Instrument [Line Items] |
|
| Interest rate |
5.76%
|
| Debt retired during the year | Maximum | Other American Water subsidiaries | Mandatorily redeemable preferred stock |
|
| Debt Instrument [Line Items] |
|
| Interest rate |
9.18%
|
| Maturity date, maximum |
2036
|
| Debt retired during the year | Maximum | Other American Water subsidiaries | Term loan |
|
| Debt Instrument [Line Items] |
|
| Interest rate |
5.81%
|
| Debt retired during the year | Fixed rate | Other American Water subsidiaries | Private activity bonds and government funded debt |
|
| Debt Instrument [Line Items] |
|
| Total retirements and redemptions |
$ 333
|
| Debt retired during the year | Fixed rate | Other American Water subsidiaries | Mortgage bonds |
|
| Debt Instrument [Line Items] |
|
| Total retirements and redemptions |
$ 28
|
| Debt retired during the year | Fixed rate | American Water Capital Corp. | Private activity bonds and government funded debt |
|
| Debt Instrument [Line Items] |
|
| Interest rate |
7.21%
|
| Total retirements and redemptions |
$ 25
|
| Debt retired during the year | Fixed rate | Minimum | Other American Water subsidiaries | Private activity bonds and government funded debt |
|
| Debt Instrument [Line Items] |
|
| Interest rate |
0.00%
|
| Maturity date, minimum |
2019
|
| Debt retired during the year | Fixed rate | Minimum | Other American Water subsidiaries | Mortgage bonds |
|
| Debt Instrument [Line Items] |
|
| Interest rate |
5.48%
|
| Maturity date, minimum |
2019
|
| Debt retired during the year | Fixed rate | Minimum | American Water Capital Corp. | Senior notes |
|
| Debt Instrument [Line Items] |
|
| Maturity date, maximum |
2019
|
| Debt retired during the year | Fixed rate | Minimum | American Water Capital Corp. | Private activity bonds and government funded debt |
|
| Debt Instrument [Line Items] |
|
| Interest rate |
1.79%
|
| Maturity date, minimum |
2021
|
| Debt retired during the year | Fixed rate | Maximum | Other American Water subsidiaries | Private activity bonds and government funded debt |
|
| Debt Instrument [Line Items] |
|
| Interest rate |
6.20%
|
| Maturity date, maximum |
2048
|
| Debt retired during the year | Fixed rate | Maximum | Other American Water subsidiaries | Mortgage bonds |
|
| Debt Instrument [Line Items] |
|
| Interest rate |
9.13%
|
| Maturity date, maximum |
2021
|
| Debt retired during the year | Fixed rate | Maximum | American Water Capital Corp. | Private activity bonds and government funded debt |
|
| Debt Instrument [Line Items] |
|
| Interest rate |
6.25%
|
| Maturity date, maximum |
2031
|