| In millions, except per share items | Jun-30-16 | Mar-31-16 | Dec-31-15 | Sep-30-15 | Jun-30-15 | Mar-31-15 | Dec-31-14 | Sep-30-14 |
| | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| Net income | 9.7 | 8.3 | 6.9 | 151.2 | 151.4 | 151.7 | 150.5 | 8.1 |
| Depreciation and amortization [+] | 3.6 | 3.5 | 3.6 | 3.6 | 3.7 | 3.8 | 3.8 | 3.9 |
| Depreciation | 1.6 | 1.4 | 1.5 | 1.5 | 1.6 | 1.3 | 1.3 | 1.4 |
| Amortization | 2.0 | 2.1 | 2.1 | 2.1 | 2.1 | 2.5 | 2.5 | 2.5 |
| Stock-based compensation | 2.4 | 2.5 | 2.5 | 0.9 | 0.8 | 0.7 | 0.9 | 0.9 |
| Deferred taxes | 8.9 | 8.1 | 7.1 | -136.2 | -140.0 | -141.1 | -142.5 | -1.1 |
| Change in working capital | -1.7 | -5.5 | -13.7 | -164.0 | -153.8 | -149.2 | -140.7 | -27.5 |
| Other | -1.7 | -5.5 | -13.7 | -164.0 | -153.8 | -149.2 | -140.7 | -27.5 |
| Other operating activities | -3.5 | 0.4 | -7.0 | 141.9 | 132.6 | 124.2 | 128.8 | 18.5 |
| Cash from operations | 19.5 | 17.3 | -0.6 | -2.7 | -5.2 | -10.0 | 0.8 | 2.9 |
| |
| Capital expenditures [+] | -1.2 | -1.7 | -2.3 | -2.0 | -2.3 | -2.3 | -2.0 | -2.6 |
| Purchases of property and equipment | -1.2 | -1.7 | -2.3 | -2.0 | -2.3 | -2.3 | -2.0 | -2.6 |
| Sales of property and equipment | | | 3.8 | 3.7 | 2.0 | 0.9 | 0.3 | 0.8 |
| Sales of short-term investments, net [+] | -1.1 | -34.4 | -62.3 | -25.2 | 60.6 | 110.0 | 143.3 | 141.8 |
| Purchases of short-term investments | | | -149.6 | -121.1 | -60.5 | -31.1 | | |
| Sales of short-term investments | 87.9 | 84.0 | 87.3 | 95.9 | 121.1 | 141.1 | 143.3 | 143.6 |
| Other cash from investing | | | -113.2 | -131.7 | -163.2 | -217.7 | -181.7 | -154.0 |
| Cash from investing | -43.5 | -87.0 | -174.1 | -155.1 | -102.9 | -109.2 | -40.1 | -13.9 |
| |
| Issuance of common stock, net | 0.1 | 0.0 | | | | | | |
| Other cash from financing | 46.6 | 85.4 | 117.9 | 125.7 | 68.6 | 62.2 | 67.8 | -31.9 |
| Cash from financing | 46.6 | 85.4 | 117.9 | 125.7 | 68.6 | 62.2 | 67.8 | -31.9 |
| |
| Free cash flow | 18.2 | 15.6 | -2.9 | -4.6 | -7.5 | -12.3 | -1.2 | 0.3 |
| Per share (diluted) | $0.75 | $0.64 | ($0.12) | ($0.20) | ($0.33) | ($0.55) | ($0.06) | $0.01 |
| |
| Cash paid for interest | 18.8 | 18.7 | 21.7 | 21.4 | 17.4 | 19.3 | 15.8 | 15.7 |
| Cash paid for income taxes | 0.4 | 0.0 | | 0.1 | | 0.0 | | |