| Dec 31, 2011 | Dec 31, 2012 | Dec 31, 2013 | Dec 31, 2014 | Dec 31, 2015 | Dec 31, 2016 | Dec 31, 2017 | Dec 31, 2018 | Dec 31, 2019 | Dec 31, 2020 | Dec 31, 2021 | Dec 31, 2022 | Dec 31, 2023 |
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| Cash and cash equivalents | 26 | 48 | 15 | 19 | 15 | 18 | 26 | 35 | 52 | 83 | 362 | 345 | 227 |
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| Short-term investments | 31 | 7 | 14 | 5 | 11 | 11 | 8 | 1 | 5 | 0 | 20 | 20 | 100 |
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| Accounts Receivable, after Allowance for Credit Loss, Current | 26 | 24 | 22 | 23 | 27 | 23 | 30 | 30 | 27 | 40 | 51 | 60 | 39 |
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| Prepaid taxes | - | - | - | - | 5 | 4 | 1 | 2 | 1 | 1 | 0 | - | 2 |
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| Prepaid expenses and other current assets | 2 | 1 | 6 | 3 | 2 | 2 | 3 | 3 | 2 | 4 | 5 | 6 | 4 |
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| Total current assets | 86 | 81 | 58 | 53 | 62 | 58 | 68 | 70 | 87 | 128 | 438 | 431 | 371 |
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| Property and equipment, net | 8 | 9 | 9 | 9 | 9 | 9 | 10 | 11 | 12 | 14 | 19 | 23 | 25 |
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| Goodwill | 93 | 94 | 94 | 94 | 94 | 93 | 94 | 94 | 94 | 179 | 197 | 192 | 194 |
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| Intangible assets, net | 8 | 7 | 5 | 3 | 1 | 1 | 1 | 1 | 1 | 109 | 110 | 96 | 89 |
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| Operating Lease, Right-of-Use Asset | - | - | - | - | - | - | - | - | 26 | 26 | 23 | 20 | 17 |
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| Deferred tax assets | - | - | - | - | - | - | - | - | - | 0 | 0 | 3 | 2 |
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| Other assets | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
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| Total assets | 211 | 220 | 177 | 177 | 178 | 170 | 173 | 176 | 222 | 457 | 789 | 765 | 700 |
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| Accounts payable | 3 | 3 | 3 | 3 | 2 | 2 | 2 | 2 | 2 | 4 | 4 | 3 | 5 |
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| Current operating lease liabilities | - | - | - | - | - | - | - | - | 3 | 4 | 4 | 4 | 4 |
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| Accrued expenses and other current liabilities | - | - | - | - | - | 3 | 3 | 3 | 2 | 17 | 17 | 11 | 9 |
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| Accrued compensation expenses | 1 | 1 | 1 | 3 | 1 | 1 | 1 | 2 | 4 | 6 | 15 | 5 | 1 |
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| Income taxes payable | 1 | 1 | - | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 8 | 3 |
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| Contract liabilities | - | - | - | - | - | - | - | 6 | 4 | 16 | 30 | 27 | 15 |
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| Total current liabilities | 15 | 15 | 14 | 17 | 15 | 18 | 24 | 15 | 16 | 46 | 70 | 58 | 37 |
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| Operating Lease, Liability, Noncurrent | - | - | - | - | - | - | - | - | 28 | 27 | 24 | 20 | 17 |
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| Convertible senior notes | - | - | - | - | - | - | - | - | - | - | 453 | 456 | 411 |
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| Deferred tax liabilities | - | - | - | - | - | - | - | - | - | 24 | 16 | 13 | 13 |
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| Total liabilities | 22 | 21 | 20 | 22 | 18 | 53 | 52 | 44 | 69 | 254 | 566 | 547 | 477 |
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| Common Stock, Value, Issued | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
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| Treasury stock, at cost; 30,243,921 and 28,896,408 shares, respectively | - | - | - | - | - | - | - | 178 | 185 | 200 | 200 | 279 | 329 |
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| Additional paid-in capital | 257 | 263 | 271 | 281 | 293 | 297 | 301 | 307 | 318 | 363 | 383 | 425 | 472 |
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| Accumulated other comprehensive loss | -0 | -0 | 0 | -0 | -0 | -0 | 0 | -0 | -0 | 2 | 0 | -10 | -5 |
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| Retained earnings | -32 | -28 | -30 | -26 | -19 | -16 | -9 | 4 | 21 | 38 | 39 | 80 | 85 |
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| Total stockholders’ equity | 190 | 199 | 157 | 156 | 160 | 118 | 121 | 133 | 153 | 203 | 223 | 217 | 223 |
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| Total liabilities and stockholders’ equity | 211 | 220 | 177 | 177 | 178 | 170 | 173 | 176 | 222 | 457 | 789 | 765 | 700 |
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