v3.10.0.1

Stock-Based Compensation (Tables) | 6 Months Ended
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Jun. 30, 2018
Stock-Based Compensation |
Schedule of stock-based compensation expense included in the consolidated statements of operations and comprehensive loss |
|  | Three Months Ended June 30, |  | Six Months Ended June 30, |
|  | 2018 |  | 2017 |  | 2018 |  | 2017 |
|  | (in thousands) |
Curriculum and teaching |  | $ | 5 |  | $ | — |  | $ | 7 |  | $ | — |
Servicing and support |  | 1,320 |  | 1,161 |  | 2,192 |  | 1,856 |
Technology and content development |  | 1,075 |  | 897 |  | 1,786 |  | 1,543 |
Marketing and sales |  | 718 |  | 430 |  | 1,207 |  | 772 |
General and administrative |  | 5,891 |  | 3,007 |  | 10,939 |  | 5,219 |
Total stock-based compensation expense |  | $ | 9,009 |  | $ | 5,495 |  | $ | 16,131 |  | $ | 9,390 |
Summary of stock option activity |
|  | Number of Options |  | Weighted-Average Exercise Price per Share |
Outstanding balance at December 31, 2017 |  | 4,559,176 |  | $ | 15.10 |
Granted |  | 655,524 |  | 84.12 |
Exercised |  | (501,531 | ) | 9.56 |
Forfeited |  | (53,531 | ) | 35.69 |
Expired |  | — |  | — |
Outstanding balance at June 30, 2018 |  | 4,659,638 |  | 25.17 |
Exercisable at June 30, 2018* |  | 3,201,819 |  | 11.26 |
*As of June 30, 2018, the aggregate intrinsic value of options exercisable was $231.5 million and such shares had a weighted-average remaining contractual term of 4.73 years.
Summary of restricted stock unit activity |
|  | Number of Restricted Stock Units |  | Weighted- Average Grant Date Fair Value |
Outstanding balance at December 31, 2017 |  | 1,413,423 |  | $ | 29.95 |
Granted |  | 440,818 |  | 81.39 |
Vested |  | (517,050 | ) | 23.34 |
Forfeited |  | (56,564 | ) | 36.38 |
Outstanding balance at June 30, 2018 |  | 1,280,627 |  | 50.04 |

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- Definition Tabular disclosure of the allocation of equity-based compensation costs to a given line item on the balance sheet and income statement for the period. This may include the reporting line for the costs and the amount capitalized and expensed. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5047-113901 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 + Details
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- Definition Tabular disclosure of the number and weighted-average grant date fair value for restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock units that were granted, vested, or forfeited during the year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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