XML 111 R94.htm IDEA: XBRL DOCUMENT
v3.22.4

SHARE-BASED AWARDS - ESPP (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based compensation expense | $ 171,000,000 | $ 536,000,000 | $ 38,000,000
Employee Stock Purchase Plan |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Calendar year limitation on contributions | $ 25,000 |  |
Number of shares allowed per employee, per offering period (in shares) | 1,000 |  |
Share-based compensation expense | $ 2,000,000 |  |
Employee Stock | Employee Stock Purchase Plan |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Payroll deductions | 15.00% |  |
Common stock discount on 1000 shares per employee | 15.00% |  |
Employee payroll contributions with held | $ 2,000,000 |  |
Estimated unrecognized compensation expense | $ 300,000 |  |
Recognized over remaining term of offering period | 2 months |  |

X
- Definition Number Of Shares Allowed Per Employee, Per Offering Period + References No definition available. + Details
Name: | open_NumberOfSharesAllowedPerEmployeePerOfferingPeriod
Namespace Prefix: | open_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Employee Payroll Contributions With Held + References No definition available. + Details
Name: | open_ShareBasedCompensationArrangementByShareBasedPaymentAwardEmployeePayrollContributionsWithHeld
Namespace Prefix: | open_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Estimated Unrecognized Compensation Expense + References No definition available. + Details
Name: | open_ShareBasedCompensationArrangementByShareBasedPaymentAwardEstimatedUnrecognizedCompensationExpense
Namespace Prefix: | open_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Share-based Compensation Arrangement By Share-Based Payment Award, Maximum Annual Contributions + References No definition available. + Details
Name: | open_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumAnnualContributions
Namespace Prefix: | open_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Recognized Over The Remaining Term Of Offering Period + References No definition available. + Details
Name: | open_ShareBasedCompensationArrangementByShareBasedPaymentAwardRecognizedOverRemainingTermOfOfferingPeriod
Namespace Prefix: | open_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
Name: | us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Discount rate from fair value on offering date that participants pay for shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Discount rate from fair value on purchase date that participants pay for shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_PlanNameAxis=open_EmployeeStockPurchasePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_EmployeeStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |