| In millions, except per share items | Sep-30-19 | Jun-30-19 | Mar-31-19 | Dec-31-18 | Sep-30-18 | Jun-30-18 | Mar-31-18 | Dec-31-17 |
| | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K |
| ASSETS | | | | | | | | |
| Current assets: | | | | | | | | |
| Cash and cash equivalents | 98.5 | 83.4 | 252.6 | 198.1 | 201.0 | 71.0 | 71.0 | 128.2 |
| Trade accounts receivable, less allowances for doubtful accounts of $1,713 and $892 | 43.4 | 47.1 | 50.5 | 31.6 | 32.6 | 32.1 | 31.2 | 22.2 |
| Prepaid expenses and other current assets | 22.9 | 22.6 | 30.7 | 10.4 | 10.1 | 10.6 | 8.7 | 6.8 |
| Total current assets | 164.8 | 153.1 | 333.8 | 240.1 | 243.6 | 113.7 | 110.8 | 157.3 |
| Property and equipment, net | 44.2 | 46.0 | 45.4 | 34.1 | 35.4 | 36.6 | 38.6 | 28.8 |
| Right-of-use lease assets | 44.8 | 48.3 | 55.2 | | | | | |
| Other assets | 24.5 | 24.2 | 26.3 | 13.9 | 13.1 | 12.3 | 10.8 | 0.8 |
| Acquired intangible assets, net | 391.8 | 417.8 | 430.3 | 118.0 | 126.5 | 134.8 | 138.6 | 45.0 |
| Goodwill | 544.0 | 543.5 | 541.2 | 155.1 | 155.3 | 155.3 | 157.2 | 81.0 |
| Total assets | 1,214.1 | 1,232.8 | 1,432.3 | 561.1 | 573.9 | 452.7 | 456.1 | 312.8 |
| |
| LIABILITIES AND STOCKHOLDERS’ EQUITY | | | | | | | | |
| Current liabilities: | | | | | | | | |
| Accounts payable | 7.4 | 7.8 | 4.9 | 2.1 | 4.1 | 5.8 | 9.6 | 10.8 |
| Accrued compensation | 20.4 | 20.9 | 21.8 | | 9.4 | 10.0 | | |
| Accrued expenses and other current liabilities | 32.5 | 29.9 | 47.6 | 15.8 | 15.8 | 34.5 | 25.2 | 11.8 |
| Current portion of deferred revenue | 183.4 | 180.1 | 172.4 | 121.6 | 121.3 | 121.0 | 116.9 | 100.2 |
| Total current liabilities | 243.6 | 238.7 | 379.1 | 151.1 | 267.2 | 155.8 | 151.6 | 132.8 |
| Long-term debt | 590.8 | 598.3 | 645.4 | 118.3 | | 195.0 | 203.4 | 111.8 |
| Long-term lease liabilities | 43.4 | 46.8 | 51.8 | | | | | |
| Deferred revenue, net of current portion | 41.6 | 43.7 | 42.4 | 29.2 | 28.0 | 27.7 | 27.5 | 24.3 |
| Long-term deferred tax liabilities | 40.3 | 43.1 | 46.3 | | | | | |
| Other long-term liabilities | 8.2 | 3.1 | 4.1 | 5.3 | 5.7 | 5.9 | 6.2 | 5.7 |
| Total liabilities | 967.9 | 973.7 | 1,169.1 | 303.9 | 301.0 | 384.3 | 388.7 | 274.6 |
| |
| Commitments and contingencies (Note 14) | | | | | | | | |
| Stockholders’ equity: | | | | | | | | |
| Common stock | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.3 | 0.3 | 0.3 |
| Additional paid-in capital | 466.7 | 461.6 | 456.0 | 451.6 | 420.4 | 243.1 | 237.9 | 233.3 |
| Treasury stock, at cost | -47.6 | -47.9 | -49.3 | -48.5 | -27.8 | -26.9 | -27.2 | -26.6 |
| Accumulated other comprehensive (loss) income | -2.3 | 2.2 | 2.0 | 1.7 | 1.5 | 1.1 | -0.1 | 0.6 |
| Accumulated deficit | -171.1 | -157.2 | -145.9 | -147.9 | -148.6 | -149.2 | -143.5 | -169.3 |
| Total stockholders’ equity | 246.1 | 259.2 | 263.2 | 257.2 | 245.8 | 68.4 | 67.4 | 38.3 |
| Total liabilities and stockholders’ equity | 1,214.1 | 1,232.8 | 1,432.3 | 561.1 | 573.9 | 452.7 | 456.1 | 312.8 |