| Current assets |
| Cash and cash equivalents |
41.6M |
| Short-term investments |
52.8M |
| Receivables, less allowances of $41.7, $27.6 and $50.1, respectively |
231.5M |
| Gas in storage |
240.2M |
| Derivative instruments |
49.6M |
| Margin accounts - derivative instruments |
27.5M |
| Other |
144.8M |
| Total current assets |
788M |
| Property, plant and equipment, at cost [Abstract] |
| Property, plant and equipment, at cost |
5.28B |
| Less accumulated depreciation |
2.17B |
| Total property, plant and equipment, net |
3.11B |
| Long-term investments |
134.6M |
| Other assets |
381.9M |
| Total assets |
4.41B |
| Current liabilities |
| Long-term debt due within one year |
0 |
| Short-term debt |
312.6M |
| Accounts payable |
305.8M |
| Customer credit balances and deposits |
109.3M |
| Temporary LIFO inventory liquidation |
| Derivative instruments |
80.3M |
| Other |
116.3M |
| Total current liabilities |
924.3M |
| Deferred credits and other liabilities |
| Regulatory asset retirement liability |
878.5M |
| Deferred income taxes |
437.1M |
| Health care and other postretirement benefits |
232.6M |
| Asset retirement obligation |
197.3M |
| Other |
140.2M |
| Total deferred credits and other liabilities |
1.89B |
| Commitments and contingencies |
0 |
| Capitalization |
| Long-term obligations |
498.5M |
| Common equity |
| Common stock |
113.9M |
| Paid-in capital |
67.5M |
| Retained earnings |
939.9M |
| Accumulated other comprehensive loss |
-19.6M |
| Total common equity |
1.1B |
| Total capitalization |
1.6B |
| Total liabilities and capitalization |
4.41B |
| Gas Distribution [Member] |
| Property, plant and equipment, at cost [Abstract] |
| Property, plant and equipment, at cost |
4.84B |
| Shipping [Member] |
| Property, plant and equipment, at cost [Abstract] |
| Property, plant and equipment, at cost |
323.7M |
| Other [Member] |
| Property, plant and equipment, at cost [Abstract] |
| Property, plant and equipment, at cost |
112.9M |
