Regulatory Matters (Narrative) (Details) - USD ($) $ in Millions |
12 Months Ended | |||
|---|---|---|---|---|
Jan. 28, 2016 |
Jan. 01, 2015 |
Jan. 24, 2013 |
Dec. 31, 2015 |
|
| Regulatory Matters [Line Items] | ||||
| Regulatory asset not earning return on investment | $ 0.0 | |||
| Expenses recovered as components of cost of service and regulatory orders | $ 7.2 | |||
| Remaining life for the costs to be recovered, years | 7 years | |||
| Customer Refund | $ 88.1 | |||
| Initial Customer Refund | 50.0 | |||
| Annual base rate reduction effective January 1, 2014 | $ 25.0 | |||
| Capital Cost Recovery Mechanism Revenue Requirement | 14.00% | |||
| Required Annual Capital Maintenance Expenditure | $ 100.0 | |||
| Annual Capital Cost Recovery Mechanism Limit | $ 1,500.0 | |||
| Annual Capital Cost Recovery Mechanism Limit Tolerance | 15.00% | |||
| Total Capital Cost Recovery Mechanism Over Five-year Term | $ 1,500.0 | |||
| Depreciation Rate Reduction | 1.50% | |||
| Expected Modernization Investment | $ 300.0 | |||
| Subsequent Event | ||||
| Regulatory Matters [Line Items] | ||||
| Expected Modernization Investment | $ 937.1 |