| In millions, except per share items | Mar-31-23 | Mar-31-22 | Mar-31-21 | Mar-31-20 | Mar-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 |
| | 10-K | 10-K | 10-K | 10-K | 8-K | 10-K | 10-K/A | 10-K |
| Cash flows from operating activities: | | | | | | | | |
| Net income | 61.5 | 21.8 | 6.2 | 17.9 | -3.1 | 15.5 | 33.5 | 5.3 |
| Adjustments to reconcile net income to net cash from operating activities: | | | | | | | | |
| Depreciation and amortization | 22.2 | 27.1 | 25.2 | 22.8 | 21.1 | 17.9 | 14.5 | 13.2 |
| Restructuring expense | | 0.1 | 2.6 | -6.0 | 22.2 | | | |
| Stock based compensation expense | 29.1 | 19.6 | 19.7 | 15.5 | 16.9 | 16.8 | 13.5 | 7.1 |
| Amortization of debt issuance costs and discount on debt | 0.3 | 0.4 | 0.8 | 0.7 | | 0.8 | 0.8 | 1.3 |
| Deferred income taxes | -6.4 | -3.7 | -8.6 | 2.4 | -5.1 | -0.9 | -13.4 | -7.6 |
| Loss on extinguishment of debt | 0.2 | 0.5 | | | | | | 2.7 |
| Other, net | 0.2 | 0.5 | 0.4 | 0.9 | | 0.5 | 1.7 | 0.2 |
| Changes in operating assets and liabilities: | | | | | | | | |
| Accounts receivable | -22.4 | -5.6 | -10.5 | 2.5 | -0.9 | 7.6 | -8.0 | -15.4 |
| Inventory | 3.2 | -27.7 | -10.9 | -0.4 | 17.9 | 16.3 | 6.7 | -38.0 |
| Prepaid expenses and other assets | -24.6 | -10.6 | -9.7 | -6.5 | 0.6 | -8.5 | -11.2 | -0.6 |
| Accounts payable and accrued expenses | 43.0 | 1.5 | 17.5 | 6.0 | 0.6 | -10.3 | -25.5 | 43.1 |
| Other liabilities | -4.4 | -4.4 | -3.3 | -11.5 | -3.5 | -0.2 | -0.2 | 1.4 |
| Net cash provided by operating activities | 101.9 | 19.5 | 29.5 | 44.3 | 58.8 | 55.6 | 12.4 | 2.1 |
| |
| Cash flows from investing activities: | | | | | | | | |
| Purchase of property and equipment | -1.7 | -4.8 | -6.5 | -9.4 | | -8.9 | -7.5 | -9.2 |
| Net cash used in investing activities | -1.7 | -4.8 | -6.5 | -35.3 | -9.6 | -8.9 | -10.4 | -9.1 |
| |
| Cash flows from financing activities: | | | | | | | | |
| Proceeds from revolving line of credit | | 26.5 | 20.0 | | | 2.0 | 25.9 | 5.5 |
| Repayment of revolving line of credit | | -26.5 | -20.0 | | | -2.0 | -25.9 | -13.2 |
| Proceeds from long-term debt | | 25.6 | | | | | | 172.7 |
| Repayment of long-term debt | -30.0 | -54.5 | -11.8 | -9.5 | | -8.3 | -8.3 | -151.5 |
| Debt issuance costs paid | | -1.1 | -0.3 | | | | -0.5 | -0.7 |
| Cash received from issuance of common stock | 8.1 | 1.7 | 1.5 | 1.5 | 3.1 | 3.2 | 2.0 | 64.1 |
| Other, net | -0.8 | -0.8 | -0.8 | -0.8 | | -0.5 | -0.4 | -0.7 |
| Net cash used in financing activities | -22.7 | -29.1 | -11.4 | -16.7 | -5.8 | -5.6 | -7.2 | 8.3 |
| Net increase (decrease) in cash and cash equivalents | 77.4 | -14.4 | 11.6 | | | | | |
| |
| Supplemental disclosure of cash flow information: | | | | | | | | |
| Cash paid for interest | 3.5 | 1.8 | 3.0 | 6.3 | | 7.1 | 8.2 | 12.2 |
| Cash paid for income taxes, net of refunds | 13.4 | 7.6 | 2.3 | 0.2 | | 4.1 | 5.7 | 8.5 |
| Cash paid for interest on finance leases | 0.0 | 0.1 | 0.1 | | | | | |
| Supplemental disclosure of noncash investing and financing activities: | | | | | | | | |
| Property and equipment purchases included in accounts payable and accrued expenses | 0.3 | 0.4 | 0.4 | 1.1 | | 1.8 | 1.1 | 0.5 |