| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| ASSETS | | | | | | | | |
| Current assets: | | | | | | | | |
| Cash and cash equivalents | 180.5 | 90.9 | 220.4 | 78.0 | 81.9 | 68.9 | 58.1 | 58.5 |
| Marketable investments | 433.7 | 379.0 | 383.2 | 242.0 | 209.9 | | | |
| Accounts receivable, net | 87.5 | 83.7 | 48.7 | 37.7 | 24.8 | 19.0 | 13.9 | 10.6 |
| Prepaid expenses and other current assets | 38.9 | 36.8 | 21.2 | 15.6 | 10.7 | 4.8 | 3.0 | 2.2 |
| Deferred contract acquisition costs, net | 47.2 | 33.3 | 20.7 | | | | | |
| Total current assets | 778.7 | 617.2 | 689.1 | 381.3 | 334.0 | 92.8 | 75.0 | 71.2 |
| Property and equipment, net | | | 51.2 | 33.2 | 25.9 | 19.9 | 14.7 | 13.2 |
| Operating lease right-of-use assets | 44.1 | 48.7 | 9.0 | 8.7 | | | | |
| Intangible assets, net | 28.2 | 39.9 | 51.7 | 15.5 | 0.6 | 1.1 | 1.5 | 2.0 |
| Goodwill | 165.4 | 165.4 | 165.4 | 11.8 | 11.8 | 11.8 | 11.8 | 11.8 |
| Marketable investments | | 147.4 | 42.1 | | | | | |
| Other assets | 11.1 | 11.9 | 3.2 | 1.2 | 0.8 | 2.6 | 2.2 | 0.9 |
| Deferred contract acquisition costs, net — less current portion | 114.9 | 84.7 | 51.9 | | | | | |
| Total assets | 1,244.5 | 1,192.9 | 1,063.7 | 482.4 | 394.7 | 128.2 | 105.2 | 99.2 |
| |
| LIABILITIES AND STOCKHOLDERS’ EQUITY | | | | | | | | |
| Current liabilities: | | | | | | | | |
| Accounts payable | 23.6 | 20.5 | 17.1 | 10.2 | 7.0 | 4.3 | 3.4 | 2.6 |
| Accrued and other current liabilities | 53.1 | 78.6 | 44.5 | 18.4 | 13.8 | 11.8 | 9.6 | |
| Operating lease liabilities | 10.6 | 9.8 | 3.9 | 5.1 | | | | |
| Accrued federal fees | 2.5 | 2.3 | 3.7 | 2.3 | 1.4 | 1.2 | 2.7 | 5.7 |
| Sales tax liabilities | 3.0 | 2.7 | 1.7 | 1.9 | 1.7 | 1.3 | 1.3 | 1.3 |
| Deferred revenue | 57.8 | 43.7 | 32.0 | 24.7 | 17.4 | 14.0 | | |
| Convertible senior notes | 0.2 | | | | | | | |
| Total current liabilities | 150.8 | 157.6 | 103.6 | 66.0 | 48.0 | 39.5 | 34.1 | 48.5 |
| Convertible senior notes — less current portion | 738.4 | 768.6 | 643.3 | 209.6 | 196.8 | | | |
| Sales tax liabilities — less current portion | 0.9 | 0.9 | 0.9 | 0.8 | 0.8 | | | |
| Operating lease liabilities — less current portion | 41.4 | 47.1 | 5.4 | 4.3 | | | | |
| Other long-term liabilities | 3.1 | 7.7 | 31.5 | 4.4 | 1.8 | 1.0 | 0.5 | 0.6 |
| Total liabilities | 934.5 | 981.8 | 784.6 | 285.9 | 251.9 | 81.4 | 74.9 | 73.0 |
| |
| Commitments and contingencies (Note 10) | | | | | | | | |
| Stockholders’ equity: | | | | | | | | |
| Common stock | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Additional paid-in capital | 635.7 | 439.8 | 476.9 | 351.9 | 294.3 | 222.2 | 196.6 | 180.6 |
| Accumulated other comprehensive loss | -2.7 | -0.3 | 0.3 | 0.6 | -0.1 | | | |
| Accumulated deficit | -323.1 | -228.4 | -198.2 | -156.0 | -151.5 | -175.4 | -166.3 | -154.4 |
| Total stockholders’ equity | 310.0 | 211.1 | 279.2 | 196.5 | 142.7 | 46.8 | 30.3 | 26.3 |
| Total liabilities and stockholders’ equity | 1,244.5 | 1,192.9 | 1,063.7 | 482.4 | 394.7 | 128.2 | 105.2 | 99.2 |