| In millions, except per share items | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 | Dec-31-14 | Dec-31-13 | Dec-31-12 | Dec-31-11 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Revenues: | | | | | | | | |
| Revenues | 179.9 | 176.4 | 181.8 | | | | | |
| |
| Expenses: | | | | | | | | |
| Expenses | | | | | | | | |
| General and administrative | 5.3 | 5.3 | 5.5 | 5.5 | 5.7 | 5.6 | 6.0 | 6.3 |
| Merger costs | 1.1 | | | | | | | |
| Depreciation | 8.2 | 8.2 | 7.7 | 8.4 | 9.1 | 9.7 | 10.3 | 11.7 |
| Total expenses | 179.0 | 176.4 | 179.7 | 13.9 | 15.2 | 195.1 | 215.6 | 227.9 |
| Operating earnings | 0.9 | 0.1 | 2.1 | 3.9 | 0.9 | 2.1 | 10.3 | 12.1 |
| Interest expense | -0.8 | -0.8 | -0.9 | -1.2 | -1.7 | -1.8 | -1.8 | -2.9 |
| Other income | 0.3 | 0.1 | 0.1 | | | | | |
| Earnings (loss) before income taxes | 0.4 | -0.6 | 1.4 | 2.7 | -0.7 | 0.4 | 8.5 | 9.2 |
| Income tax expense | -0.4 | -0.5 | -0.6 | -0.8 | 0.0 | -0.4 | -3.7 | -3.8 |
| Net earnings (loss) | 0.0 | -1.1 | 0.8 | 1.9 | -0.7 | 0.0 | 4.8 | 5.4 |
| Change in pension net actuarial loss and prior service cost, net of income taxes | -0.2 | -0.1 | -0.4 | 0.5 | -3.6 | 2.1 | | |
| Unrealized gain on available-for-sale securities, net of income taxes | | 0.0 | 0.0 | | | | | |
| Comprehensive (loss) income | -0.1 | -1.2 | 0.4 | 2.3 | -4.3 | 2.2 | 3.8 | 4.7 |
| |
| Net earnings (loss) per common share (Note 3): | | | | | | | | |
| Basic (in dollars per share) | | 0.0 | 0.0 | 0.0 | 0.0 | | | |
| |
| Diluted (in dollars per share) | | ($0.04) | $0.02 | $0.06 | ($0.02) | | $0.15 | $0.17 |