Debt, Long-term and Short-term, Combined Amount, Gross

No definition available.

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Namespace Prefix:	ondk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

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Balance Type:	na
Period Type:	duration

- Definition

Represents the aggregate of total long-term debt, including current maturities and short-term debt.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ 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 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28555-108399

+ Details

Name:	us-gaap_DeferredFinanceCostsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585

+ Details

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Balance Type:	credit
Period Type:	duration

- Details

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Debt (Summary of Outstanding Debt) (Details) - USD ($)			1 Months Ended	9 Months Ended
Debt (Summary of Outstanding Debt) (Details) - USD ($)	Aug. 14, 2018	Aug. 08, 2018	Apr. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Revolving Credit Facility
Debt Instrument [Line Items]
Weighted Average Interest Rate at September 30, 2018				4.60%
ODAST II Series 2018-1 \| Secured Debt
Debt Instrument [Line Items]
Weighted Average Interest Rate at September 30, 2018				3.80%
Debt				$ 225,000,000		$ 0
Debt instrument, face amount			$ 225,000,000
ODAST II Series 2016-1 \| Secured Debt
Debt Instrument [Line Items]
Debt				$ 0		250,000,000
Amount of debt repaid			$ 250,000,000
ODART \| Revolving Credit Facility
Debt Instrument [Line Items]
Weighted Average Interest Rate at September 30, 2018				4.70%
Debt				$ 120,985,000		102,058,000
RAOD \| Revolving Credit Facility
Debt Instrument [Line Items]
Weighted Average Interest Rate at September 30, 2018				5.30%
Debt				$ 111,542,000		86,478,000
ODAC \| Revolving Credit Facility
Debt Instrument [Line Items]
Debt				0		62,350,000
Amount of debt repaid		$ 100,000,000
ODAF \| Revolving Credit Facility
Debt Instrument [Line Items]
Debt				$ 0		75,000,000
Amount of debt repaid	$ 150,000,000
ODAF II \| Revolving Credit Facility
Debt Instrument [Line Items]
Weighted Average Interest Rate at September 30, 2018				4.40%
Debt				$ 111,119,000		0
PORT II \| Revolving Credit Facility
Debt Instrument [Line Items]
Weighted Average Interest Rate at September 30, 2018				4.70%
Debt				$ 110,605,000		63,851,000
LAOD \| Revolving Credit Facility
Debt Instrument [Line Items]
Weighted Average Interest Rate at September 30, 2018				4.10%
Debt				$ 95,096,000		0
Other Agreements \| Revolving Credit Facility
Debt Instrument [Line Items]
Weighted Average Interest Rate at September 30, 2018				7.40%
Debt				$ 44,194,000		50,706,000
Funding debt
Debt Instrument [Line Items]
Debt				818,541,000		690,443,000
Deferred debt issuance cost				(6,113,000)		(6,174,000)
Total				812,428,000		684,269,000
Amount of debt repaid				544,586,000	$ 156,477,000
Corporate debt
Debt Instrument [Line Items]
Total				0		7,985,000
Amount of debt repaid				$ 33,000,000	$ 35,000,000
Corporate debt \| Revolving Credit Facility
Debt Instrument [Line Items]
Weighted Average Interest Rate at September 30, 2018				6.50%
Debt				$ 0		8,000,000
Deferred debt issuance cost				$ 0		$ (15,000)