v3.8.0.1

Segment and Geographic Information - Concentration Risk (Details) $ in Thousands |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jul. 01, 2017 segment | Dec. 31, 2017 USD ($) | Sep. 30, 2017 USD ($) | Jun. 30, 2017 USD ($) | Mar. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Sep. 30, 2016 USD ($) | Jun. 30, 2016 USD ($) | Mar. 31, 2016 USD ($) | Dec. 31, 2017 USD ($) client | Dec. 31, 2016 USD ($) client | Dec. 31, 2015 USD ($)
Segment Information |  |  |  |  |  |  |  |  |  |  |  |
Number of operating segments | segment | 2 |  |  |  |  |  |  |  |  |  |  |
Number of reportable segments | segment | 2 |  |  |  |  |  |  |  |  |  |  |
Revenue |  | $ 86,678 | $ 70,250 | $ 64,995 | $ 64,829 | $ 57,350 | $ 51,960 | $ 49,110 | $ 47,444 | $ 286,752 | $ 205,864 | $ 150,194
Accounts receivable, net |  | 14,174 |  |  |  | 7,860 |  |  |  | 14,174 | 7,860 |
Graduate Program Segment |  |  |  |  |  |  |  |  |  |  |  |
Segment Information |  |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  |  | 270,432 | $ 205,864 | $ 150,194
Short Course Segment |  |  |  |  |  |  |  |  |  |  |  |
Segment Information |  |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  |  | $ 16,320 |  |
Customer concentration risk | Revenue | Graduate Program Segment |  |  |  |  |  |  |  |  |  |  |  |
Segment Information |  |  |  |  |  |  |  |  |  |  |  |
Number of clients who account for more then 10% | client |  |  |  |  |  |  |  |  |  | 4 | 3 |
Customer concentration risk | Revenue | Short Course Segment |  |  |  |  |  |  |  |  |  |  |  |
Segment Information |  |  |  |  |  |  |  |  |  |  |  |
Percentage of concentration of credit risk |  |  |  |  |  |  |  |  |  | 82.00% |  |
Credit concentration risk | Accounts receivable | Graduate Program Segment |  |  |  |  |  |  |  |  |  |  |  |
Segment Information |  |  |  |  |  |  |  |  |  |  |  |
Number of clients who account for more then 10% | client |  |  |  |  |  |  |  |  |  | 2 | 2 |
University client A | Customer concentration risk | Revenue | Graduate Program Segment |  |  |  |  |  |  |  |  |  |  |  |
Segment Information |  |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  |  | $ 77,600 | $ 71,000 |
Percentage of concentration of credit risk |  |  |  |  |  |  |  |  |  | 27.00% | 35.00% |
University client A | Credit concentration risk | Accounts receivable | Graduate Program Segment |  |  |  |  |  |  |  |  |  |  |  |
Segment Information |  |  |  |  |  |  |  |  |  |  |  |
Accounts receivable, net |  | 9,400 |  |  |  | 5,800 |  |  |  | $ 9,400 | $ 5,800 |
Percentage of concentration of credit risk |  |  |  |  |  |  |  |  |  | 67.00% | 74.00% |
University client B | Customer concentration risk | Revenue | Graduate Program Segment |  |  |  |  |  |  |  |  |  |  |  |
Segment Information |  |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  |  | $ 48,200 | $ 36,700 |
Percentage of concentration of credit risk |  |  |  |  |  |  |  |  |  | 17.00% | 18.00% |
University client B | Credit concentration risk | Accounts receivable | Graduate Program Segment |  |  |  |  |  |  |  |  |  |  |  |
Segment Information |  |  |  |  |  |  |  |  |  |  |  |
Accounts receivable, net |  | $ 2,000 |  |  |  | $ 1,400 |  |  |  | $ 2,000 | $ 1,400 |
Percentage of concentration of credit risk |  |  |  |  |  |  |  |  |  | 14.00% | 17.00% |
University client C | Customer concentration risk | Revenue | Graduate Program Segment |  |  |  |  |  |  |  |  |  |  |  |
Segment Information |  |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  |  | $ 30,100 | $ 22,100 |
Percentage of concentration of credit risk |  |  |  |  |  |  |  |  |  | 11.00% | 11.00% |
University client D | Customer concentration risk | Revenue | Graduate Program Segment |  |  |  |  |  |  |  |  |  |  |  |
Segment Information |  |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  |  | $ 28,300 |  |
Percentage of concentration of credit risk |  |  |  |  |  |  |  |  |  | 10.00% |  |

X
- Definition Number of clients for concentration risk + References No definition available. + Details
Name: | twou_NumberOfClients
Namespace Prefix: | twou_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(3)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(4)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_AccountsReceivableNetCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611 + Details
Name: | us-gaap_ConcentrationRiskPercentage1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues. + References No definition available. + Details
Name: | us-gaap_NumberOfOperatingSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References No definition available. + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate revenue during the period from services rendered in the normal course of business, after deducting allowances and discounts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1(d)) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
Name: | us-gaap_SalesRevenueServicesNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_SegmentReportingInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=twou_GraduateProgramSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=twou_ShortCourseSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueServicesNetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CreditConcentrationRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_AccountsReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=twou_UniversityClientOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=twou_UniversityClientTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=twou_UniversityClientThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorCustomersAxis=twou_UniversityClientFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |