| In millions, except per share items | Sep-30-13 | Jun-30-13 | Mar-31-13 | Dec-31-12 | Sep-30-12 | Jun-30-12 | Mar-31-12 | Dec-31-11 |
| | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q |
| Operating Activities: | | | | | | | | |
| Net income | 21.9 | 24.4 | 26.9 | 37.7 | 49.8 | 56.5 | 51.5 | 36.9 |
| Adjustments to reconcile net income to net cash from operating activities: | | | | | | | | |
| Depreciation and amortization | 21.1 | 20.9 | 20.7 | 21.4 | 21.8 | 22.0 | 21.6 | 19.0 |
| Provision for doubtful accounts | -0.3 | -0.4 | 0.2 | 0.5 | 0.9 | 1.0 | 0.9 | 1.2 |
| Deferred income taxes | 6.6 | 8.0 | 9.2 | 10.1 | 10.3 | 10.3 | 13.0 | 10.4 |
| Stock compensation expense | 6.6 | 6.6 | 6.5 | 6.2 | 6.1 | 6.1 | 6.4 | 6.3 |
| Changes in operating assets and liabilities (net of impact of acquisition): | | | | | | | | |
| Accounts receivable | 12.5 | 3.9 | -1.6 | 0.4 | -14.4 | -9.5 | -9.5 | -15.3 |
| Inventories | 4.0 | 7.0 | 6.7 | 5.1 | 3.5 | -6.2 | -9.1 | -18.2 |
| Prepaid expenses and other current assets | -2.0 | -0.7 | 0.3 | 0.6 | 0.6 | 1.5 | -0.1 | -2.1 |
| Other assets | -0.2 | 0.0 | -0.2 | 0.8 | 1.0 | 1.0 | 1.1 | 0.2 |
| Accounts payable | -12.2 | -11.5 | -7.1 | 5.2 | 15.6 | 18.9 | 24.1 | 8.4 |
| Deferred revenues | 3.4 | 3.0 | 1.6 | -5.5 | -4.2 | -5.6 | -9.3 | 4.3 |
| Accrued payroll and related fringe benefits | -4.5 | -7.0 | -5.6 | -3.2 | -1.4 | -0.8 | 0.0 | -1.1 |
| Other accrued expenses | -0.4 | -0.5 | -3.3 | -1.6 | -1.4 | -1.5 | -1.8 | -0.4 |
| Other liabilities | | -0.3 | -0.3 | 0.1 | 0.2 | | -0.4 | -0.6 |
| Net cash provided by operating activities | 60.2 | 57.3 | 53.5 | 69.6 | 69.5 | 68.6 | 65.9 | 37.0 |
| |
| Investing Activities: | | | | | | | | |
| Purchases of fixed assets | -19.8 | -20.5 | -23.3 | -23.6 | -22.8 | -21.7 | -19.2 | -16.2 |
| Acquisition of business | -3.8 | | | | | | | |
| Net cash used in investing activities | -32.9 | -34.6 | -37.4 | -37.5 | -36.5 | -35.2 | -51.3 | -44.4 |
| |
| Financing Activities: | | | | | | | | |
| Proceeds from exercise of stock options | 1.3 | 1.1 | 1.0 | 1.8 | 2.0 | 2.3 | 2.8 | 3.0 |
| Proceeds from exercise of warrants | 2.3 | 1.3 | 0.5 | | | 0.1 | 0.1 | |
| Repayments of debt | -10.7 | -10.7 | -10.7 | -10.7 | -10.7 | -10.7 | -10.4 | -7.7 |
| Net cash used in financing activities | -7.0 | -8.4 | -9.1 | -8.8 | -8.5 | -8.3 | 10.5 | 13.3 |
| Effect of foreign currency translation on cash and cash equivalents | -0.1 | -0.1 | 0.2 | 0.1 | -0.1 | -0.3 | -0.7 | -0.2 |
| Net increase (decrease) in cash and cash equivalents | 20.1 | 14.3 | 7.2 | 23.4 | 24.4 | 24.8 | 24.4 | 5.7 |
| Cash and cash equivalents at beginning of period | 231.7 | | 216.6 | 192.4 | 168.1 | | 143.9 | 138.8 |
| Cash and cash equivalents at end of period | 251.8 | 230.8 | 223.8 | 215.8 | 192.6 | 168.7 | 168.3 | 144.5 |
| |
| Supplemental Disclosure of Cash Flow Information | | | | | | | | |
| Cash paid for interest | 0.7 | 0.7 | 0.8 | 0.9 | 1.0 | 1.1 | 1.1 | 0.9 |
| Cash paid for income taxes | 1.6 | 1.6 | 0.9 | 1.3 | 1.2 | 1.2 | 0.9 | 0.9 |