v3.19.3.a.u2

Stockholders' Equity (Details) - USD ($) $ in Thousands |  |  |  | 12 Months Ended
--- | --- | --- | --- | ---
May 22, 2019 | May 22, 2018 | Sep. 11, 2017 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Stockholders' Equity |  |  |  |  |  |
Proceeds from issuance of common stock, net of offering costs |  | $ 330,900 | $ 189,500 | $ 0 | $ 330,901 | $ 189,463
Authorized shares of capital stock (in shares) |  |  |  | 205,000,000 |  |
Authorized shares of common stock (in shares) |  |  |  | 200,000,000 | 200,000,000 |
Authorized shares of preferred stock (in shares) |  |  |  | 5,000,000 | 5,000,000 |
Shares of common stock reserved for future issuance |  |  |  |  |  |
Outstanding stock options (in shares) |  |  |  | 4,373,895 |  |
Outstanding restricted stock units (in shares) |  |  |  | 3,694,915 |  |
Available for future issuance under Amended and Restated 2014 Equity Incentive Plan (in shares) |  |  |  | 5,296,333 |  |
Available for future issuance under employee stock purchase plan (in shares) |  |  |  | 812,964 |  |
Total shares of common stock reserved for future issuance (in shares) |  |  |  | 14,178,107 |  |
Common Stock |  |  |  |  |  |
Stockholders' Equity |  |  |  |  |  |
Issuance of common stock award (in shares) | 4,608,101 | 3,833,334 | 4,047,500 | 4,608,101 | 3,833,334 | 4,047,500
Common Stock | Underwriters' over-allotment option |  |  |  |  |  |
Stockholders' Equity |  |  |  |  |  |
Issuance of common stock award (in shares) |  | 500,000 | 547,500 |  |  |

X
- Definition The maximum number of shares of capital stock permitted to be issued by the entity's charter and bylaws. + References No definition available. + Details
Name: | twou_CapitalStockSharesAuthorized
Namespace Prefix: | twou_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- References No definition available. + Details
Name: | twou_CommonStockCapitalSharesReservedForFutureIssuanceAbstract
Namespace Prefix: | twou_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of common shares reserved for future issuance pertaining to available for future issuance under employee stock purchase plan. + References No definition available. + Details
Name: | twou_CommonStockCapitalSharesReservedForFutureIssuanceAvailableForFutureIssuanceUnderStockPurchasePlan
Namespace Prefix: | twou_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of outstanding restricted stock units reserved for future issuance pertaining to possible future issuance under stock option plans. + References No definition available. + Details
Name: | twou_CommonStockCapitalSharesReservedForFutureIssuanceOutstandingRestrictedStockUnits
Namespace Prefix: | twou_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of common shares reserved for future issuance pertaining to outstanding stock options. + References No definition available. + Details
Name: | twou_CommonStockCapitalSharesReservedForFutureIssuanceOutstandingStockOptions
Namespace Prefix: | twou_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of common shares reserved for future issuance pertaining to possible future issuance under stock option plans. + References No definition available. + Details
Name: | twou_CommonStockCapitalSharesReservedForFutureIssuancePossibleFutureIssuanceUnderStockOptionPlans
Namespace Prefix: | twou_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate number of common shares reserved for future issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maximum number of common shares permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_PreferredStockSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash inflow from the additional capital contribution to the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of new stock issued during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
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_SubsidiarySaleOfStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=us-gaap_OverAllotmentOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |