| In millions, except per share items | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 | Dec-31-14 | Dec-31-13 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Assets | | | | | | | | |
| Current assets: | | | | | | | | |
| Cash and cash equivalents | 102.2 | 51.3 | 49.2 | 59.9 | 71.9 | 75.9 | 62.1 | 75.4 |
| Accounts receivable, net of allowance for doubtful accounts of $2,188 and $2,402, respectively | 116.9 | 107.8 | 144.9 | 116.7 | 103.3 | 82.1 | 84.4 | 52.3 |
| Contract assets | 32.4 | 28.2 | 23.0 | | | | | |
| Inventories | 79.0 | 80.5 | 84.5 | 80.3 | 66.1 | 46.5 | 51.2 | 34.9 |
| Taxes receivable | 6.7 | 3.4 | 2.9 | 5.5 | 3.9 | 4.2 | 4.5 | 1.6 |
| Prepaid expenses | | 3.8 | 4.7 | 4.9 | 4.1 | 3.0 | | |
| Other current assets | 12.2 | 12.3 | 12.5 | 11.0 | 10.3 | 10.5 | 11.1 | 8.0 |
| Total current assets | 349.4 | 283.6 | 317.1 | 273.5 | 255.6 | 219.3 | 213.3 | 172.3 |
| Property, plant and equipment, at cost | 19.9 | 26.0 | 438.6 | 380.6 | 343.1 | 290.5 | 295.2 | 258.7 |
| Accumulated depreciation | | -265.7 | -244.7 | -226.8 | -199.2 | -188.2 | -189.5 | -186.6 |
| Property, plant and equipment, net | | 221.6 | 213.4 | 170.3 | 160.8 | 114.4 | 115.4 | 78.9 |
| Operating lease right-of-use assets | 22.2 | 23.1 | | | | | | |
| Goodwill | 87.6 | 133.9 | 197.0 | 69.0 | 63.6 | 16.8 | 21.9 | 18.6 |
| Other intangible assets, net | 95.1 | 115.6 | 136.6 | 40.5 | 41.4 | 5.4 | 17.0 | 10.6 |
| Other assets, net | 5.3 | 6.2 | 6.6 | 6.4 | 5.3 | 2.3 | 1.9 | 0.9 |
| Total assets | 775.5 | 785.9 | 872.7 | 560.9 | 527.0 | 358.3 | 361.8 | 274.7 |
| |
| Liabilities and Stockholders' Equity | | | | | | | | |
| Current liabilities: | | | | | | | | |
| Current portion of long-term debt | 9.8 | 9.9 | 10.2 | 0.3 | 0.6 | 0.3 | 0.6 | 0.7 |
| Accounts payable | 101.9 | 73.4 | 73.3 | 71.9 | 56.3 | 42.5 | 49.3 | 29.8 |
| Accrued payroll and other compensation | 24.6 | 17.2 | 16.6 | 16.0 | 14.0 | 10.2 | 14.6 | 10.4 |
| Accrued taxes | 8.2 | 5.6 | 3.1 | 2.2 | 6.5 | 1.2 | 1.4 | 1.8 |
| Derivative liabilities | 12.0 | 6.4 | | | | | | |
| Restructuring liabilities | 9.4 | 0.1 | | | | | | |
| Other accrued liabilities | 21.7 | 17.2 | 14.3 | 8.3 | 13.0 | 6.8 | 7.1 | 6.0 |
| Total current liabilities | 187.6 | 129.9 | 121.3 | 102.1 | 90.4 | 61.0 | 73.1 | 48.7 |
| Long-term debt | | 262.7 | 314.6 | 76.9 | 128.1 | 20.2 | 40.3 | 1.1 |
| Deferred tax liabilities | 27.2 | 34.6 | 39.3 | 14.7 | 15.8 | 15.0 | 13.9 | 8.7 |
| Benefit plan liabilities | 21.7 | 19.0 | 22.8 | 9.7 | 14.7 | 14.2 | 19.1 | 14.1 |
| Other long-term liabilities | 2.7 | 3.0 | 5.4 | 4.0 | 4.4 | 2.7 | 2.8 | 2.0 |
| |
| Commitments and Contingencies (Note 16) | | | | | | | | |
| Stockholders' equity: | | | | | | | | |
| Common stock | 0.3 | 0.3 | 0.3 | 0.3 | 0.2 | 0.2 | 2.5 | 2.4 |
| Capital in excess of par value | 99.8 | 94.1 | 90.9 | 88.0 | 82.4 | 76.7 | 69.0 | 62.3 |
| Retained earnings | 266.9 | 340.6 | 411.3 | 374.8 | 325.5 | 288.4 | 242.1 | 220.3 |
| Accumulated other comprehensive income (loss) | -18.3 | -26.0 | -42.7 | -20.1 | -48.0 | -34.6 | -24.2 | -8.8 |
| Total stockholders' equity | 257.7 | 318.4 | 369.3 | 353.4 | 273.5 | 245.2 | 212.6 | 200.1 |
| Total liabilities and stockholders’ equity | 775.5 | 785.9 | 872.7 | 560.9 | 527.0 | 358.3 | 361.8 | 274.7 |