Long-Term Debt and Credit Facilities - Revolving Letters of Credit (Details) $ in Millions	Dec. 31, 2024 USD ($)
Long-term Debt and Credit Facilities
Letters of credit outstanding	$ 220
Facility Maintained by the Subsidiary
Long-term Debt and Credit Facilities
Letters of credit outstanding	2
Letter of Credit | Uncommitted Revolving Letter of Credit Facility
Long-term Debt and Credit Facilities
Maximum borrowing capacity	225
Letters of credit outstanding	1
Revolving Credit Facility
Long-term Debt and Credit Facilities
Letters of credit outstanding	$ 217