| In millions, except per share items | Mar-31-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 |
| | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K |
| Assets | | | | | | | | |
| Current assets: | | | | | | | | |
| Cash and cash equivalents | 48.2 | 31.5 | 14.3 | 52.4 | 34.1 | 65.0 | 34.7 | 83.9 |
| Accounts receivable, less allowances (March 31, 2023—$1,100 and June 30, 2022—$1,320) | 163.4 | 182.1 | 149.3 | 153.9 | 137.7 | 121.6 | 144.9 | 148.0 |
| Costs and estimated earnings in excess of billings on uncompleted contracts | 53.4 | 46.6 | 59.6 | 44.8 | 46.4 | 34.5 | 33.8 | 30.8 |
| Inventories | 8.0 | 8.0 | 8.4 | 10.0 | 6.9 | 6.3 | 6.3 | 7.3 |
| Income taxes receivable | 0.5 | 13.5 | 13.5 | 13.5 | 13.7 | 16.2 | 16.8 | 17.0 |
| Other current assets | 4.8 | 4.7 | 5.6 | 12.9 | 7.3 | 8.5 | 11.2 | 4.2 |
| Total current assets | 284.8 | 294.5 | 260.6 | 287.4 | 246.1 | 254.7 | 250.3 | 291.2 |
| Property, plant and equipment, net | 50.5 | 50.7 | 51.7 | 53.9 | 60.5 | 62.7 | 65.8 | 69.4 |
| Operating lease right-of-use assets | 22.9 | 23.9 | 21.2 | 22.1 | 20.8 | 20.4 | 21.5 | 22.4 |
| Goodwill | 29.7 | 29.7 | 41.9 | 42.1 | 42.2 | 60.5 | 60.5 | 60.6 |
| Other intangible assets, net of accumulated amortization | 3.5 | 3.9 | 4.4 | 4.8 | 5.2 | 5.7 | 6.1 | 6.6 |
| |
| Deferred income taxes | | | | | | | | |
| Other assets, non-current | 9.5 | 10.4 | 6.2 | 5.5 | 13.2 | 11.5 | 10.4 | 12.0 |
| Total assets | 425.9 | 438.1 | 410.9 | 440.8 | 413.1 | 440.6 | 450.3 | 467.6 |
| |
| Liabilities and stockholders’ equity | | | | | | | | |
| Current liabilities: | | | | | | | | |
| Accounts payable | 65.5 | 80.6 | 68.6 | 74.9 | 68.2 | 56.0 | 66.0 | 60.9 |
| Billings on uncompleted contracts in excess of costs and estimated earnings | 114.7 | 99.8 | 53.3 | 65.1 | 73.9 | 84.9 | 51.0 | 53.8 |
| Accrued wages and benefits | 13.3 | 12.4 | 16.6 | 21.5 | 23.1 | 16.0 | 20.2 | 21.0 |
| Accrued insurance | 5.8 | 5.8 | 7.0 | 6.1 | 6.3 | 6.2 | 6.6 | 6.6 |
| Operating lease liabilities | 4.6 | 4.5 | 4.9 | 5.7 | 4.9 | 5.4 | 5.6 | 5.7 |
| Other accrued expenses | 4.5 | 5.5 | 4.2 | 4.4 | 3.8 | 5.6 | 4.9 | 5.3 |
| Total current liabilities | 208.4 | 208.6 | 154.6 | 177.8 | 180.2 | 173.9 | 154.3 | 153.4 |
| Deferred income taxes | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Operating lease liabilities | 21.7 | 22.7 | 19.7 | 19.9 | 19.6 | 18.9 | 20.0 | 20.8 |
| Borrowings under asset-backed credit facility | 15.0 | 15.0 | 15.0 | 15.0 | | | | |
| Other liabilities | 0.8 | 0.4 | 0.3 | 0.4 | 0.4 | 2.1 | 7.7 | 7.8 |
| Total liabilities | 245.9 | 246.7 | 189.7 | 213.1 | 200.2 | 195.0 | 182.0 | 182.0 |
| |
| Commitments and contingencies | | | | | | | | |
| Stockholders' equity: | | | | | | | | |
| Common stock—$.01 par value; 60 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 |
| Additional paid-in capital | 139.3 | 138.0 | 137.7 | 139.9 | 137.9 | 135.9 | 135.3 | 137.6 |
| Retained earnings | 59.3 | 71.9 | 104.8 | 111.3 | 97.8 | 132.7 | 157.6 | 175.2 |
| Accumulated other comprehensive loss | -8.9 | -8.7 | -9.9 | -8.2 | -7.5 | -7.4 | -7.5 | -6.7 |
| Stockholders' equity | 189.9 | 201.5 | 232.8 | 243.2 | 228.5 | 261.5 | 285.7 | 306.3 |
| Treasury stock, at cost — 850,661 shares as of March 31, 2023, and 1,097,703 shares as of June 30, 2022 | -9.9 | -10.1 | -11.5 | -15.5 | -15.7 | -15.9 | -17.4 | -20.7 |
| Total stockholders' equity | 180.0 | 191.5 | 221.3 | 227.7 | 212.8 | 245.6 | 268.3 | 285.5 |
| Total liabilities and stockholders’ equity | 425.9 | 438.1 | 410.9 | 440.8 | 413.1 | 440.6 | 450.3 | 467.6 |