| In millions, except per share items | Dec-31-14 | Dec-31-13 | Dec-31-12 | Dec-31-11 | Dec-31-10 | Dec-31-09 |
| | 10-K | 10-K | 10-K | 10-K | S-1 | S-1 |
| Net income | -26.3 | 6.3 | -5.9 | -4.4 | -6.0 | -5.5 |
| Depreciation and amortization [+] | 3.9 | 2.3 | 1.5 | 0.5 | 0.3 | 0.2 |
| Depreciation | 3.1 | 2.3 | 1.5 | 0.5 | 0.3 | 0.2 |
| Amortization of intangible assets | 0.8 | | | | | |
| Stock-based compensation | 9.4 | 4.1 | 2.4 | 0.9 | 0.6 | 0.3 |
| Change in working capital [+] | 8.7 | 1.7 | -1.4 | 1.1 | -0.5 | -0.4 |
| Other current assets | -1.1 | 0.6 | -2.8 | -0.4 | | |
| Other | 9.9 | 1.1 | 1.4 | 1.5 | -0.5 | -0.4 |
| Other operating activities | -35.8 | -23.1 | 2.6 | -10.3 | -2.6 | -1.0 |
| Cash from operations | -40.1 | -8.7 | -0.8 | -12.1 | -8.3 | -6.5 |
| |
| Capital expenditures | -14.5 | -3.4 | -3.2 | -1.7 | -0.9 | -0.1 |
| Purchases of property and equipment | -14.5 | -3.4 | -3.2 | -1.7 | -0.9 | -0.1 |
| Acquisitions | -8.9 | | | | | |
| Purchases of short-term investments, net | -8.5 | -80.6 | -5.2 | -8.4 | -10.5 | 4.7 |
| Purchases of short-term investments | -158.3 | -142.4 | -37.5 | -23.1 | -30.7 | -3.6 |
| Sales of short-term investments | 149.8 | 61.8 | 32.2 | 14.7 | 20.2 | 8.3 |
| Other cash from investing | -3.2 | 1.5 | -7.6 | -0.2 | -1.0 | |
| Cash from investing | -35.1 | -82.5 | -16.1 | -10.3 | -12.4 | 4.6 |
| |
| Issuance of common stock, net | | 88.4 | | | | 0.0 |
| Option exercises | 3.3 | 3.9 | 0.1 | 0.2 | | |
| Other cash from financing | 34.7 | 72.6 | 13.8 | 50.0 | 19.5 | 15.2 |
| Cash from financing | 31.3 | 157.1 | 13.6 | 49.9 | 19.5 | 15.2 |
| |
| Free cash flow | -54.6 | -12.1 | -4.0 | -13.8 | -9.2 | -6.6 |
| Per share (diluted) | ($1.43) | ($0.32) | ($0.78) | ($2.78) | ($1.93) | ($1.42) |
| |
| Cash paid for interest | 1.0 | 2.1 | 1.7 | 0.4 | | |