Long-Term Debt - Issued (Details) - USD ($)
$ in Millions |
|
12 Months Ended |
May 13, 2019 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
| Debt Instrument [Line Items] |
|
|
|
|
| Interest rate |
|
2.45%
|
|
|
| Total issuances |
|
$ 1,530
|
$ 1,358
|
$ 1,395
|
| Other American Water subsidiaries | Private activity bonds and government funded debt | Private Activity Bonds And Government Funded, Issued In 2017 |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Total issuances |
|
$ 330
|
|
|
| Other American Water subsidiaries | Private activity bonds and government funded debt | Minimum | Private Activity Bonds And Government Funded, Issued In 2017 |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Interest rate |
|
0.00%
|
|
|
| Maturity date |
|
2021
|
|
|
| Other American Water subsidiaries | Private activity bonds and government funded debt | Maximum | Private Activity Bonds And Government Funded, Issued In 2017 |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Interest rate |
|
5.00%
|
|
|
| Maturity date |
|
2048
|
|
|
| American Water Capital Corp. | Senior notes |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Total issuances |
$ 1,090
|
|
|
|
| American Water Capital Corp. | Senior notes | Senior Notes, Issued In 2017 |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Total issuances |
|
$ 1,100
|
|
|
| American Water Capital Corp. | Senior notes | Minimum | Senior Notes, Issued In 2017 |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Interest rate |
|
3.45%
|
|
|
| Maturity date |
|
2029
|
|
|
| American Water Capital Corp. | Senior notes | Maximum | Senior Notes, Issued In 2017 |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Interest rate |
|
4.15%
|
|
|
| Maturity date |
|
2049
|
|
|
| American Water Capital Corp. | Private activity bonds and government funded debt |
|
|
|
|
| Debt Instrument [Line Items] |
|
|
|
|
| Maturity date |
|
2039
|
|
|
| Total issuances |
|
$ 100
|
|
|