REVENUE - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2018	[1],[2],[3],[4],[5],[6],[7]	Sep. 30, 2018	[1],[2],[3],[4],[5],[6],[7]	Jun. 30, 2018	[1],[2],[3],[4],[5],[6],[7]	Mar. 31, 2018	[1],[2],[3],[4],[5],[6],[7]	Dec. 31, 2017	[7],[8]	Sep. 30, 2017	[7],[8]	Jun. 30, 2017	[7],[8]	Mar. 31, 2017	[7],[8]	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenue	$ 217,633		$ 204,575		$ 218,556		$ 197,438		$ 216,066		$ 234,979		$ 250,685		$ 240,483		$ 838,202	$ 942,213	$ 997,303
Revenue recognized when services are performed or assets are sold
Disaggregation of Revenue [Line Items]
Revenue																	719,739
Revenue related to technology platforms and professional services
Disaggregation of Revenue [Line Items]
Revenue																	88,424
Reimbursable expenses revenue
Disaggregation of Revenue [Line Items]
Revenue																	30,039
Operating Segment | Mortgage Market
Disaggregation of Revenue [Line Items]
Revenue																	686,905	793,684	827,324
Operating Segment | Mortgage Market | Revenue recognized when services are performed or assets are sold
Disaggregation of Revenue [Line Items]
Revenue																	575,758
Operating Segment | Mortgage Market | Revenue related to technology platforms and professional services
Disaggregation of Revenue [Line Items]
Revenue																	82,691
Operating Segment | Mortgage Market | Reimbursable expenses revenue
Disaggregation of Revenue [Line Items]
Revenue																	28,456
Operating Segment | Mortgage Market | Servicer Solutions
Disaggregation of Revenue [Line Items]
Revenue																	639,150
Operating Segment | Mortgage Market | Servicer Solutions | Revenue recognized when services are performed or assets are sold
Disaggregation of Revenue [Line Items]
Revenue																	537,161
Operating Segment | Mortgage Market | Servicer Solutions | Revenue related to technology platforms and professional services
Disaggregation of Revenue [Line Items]
Revenue																	73,782
Operating Segment | Mortgage Market | Servicer Solutions | Reimbursable expenses revenue
Disaggregation of Revenue [Line Items]
Revenue																	28,207
Operating Segment | Mortgage Market | Origination Solutions
Disaggregation of Revenue [Line Items]
Revenue																	47,755
Operating Segment | Mortgage Market | Origination Solutions | Revenue recognized when services are performed or assets are sold
Disaggregation of Revenue [Line Items]
Revenue																	38,597
Operating Segment | Mortgage Market | Origination Solutions | Revenue related to technology platforms and professional services
Disaggregation of Revenue [Line Items]
Revenue																	8,909
Operating Segment | Mortgage Market | Origination Solutions | Reimbursable expenses revenue
Disaggregation of Revenue [Line Items]
Revenue																	249
Operating Segment | Real Estate Market
Disaggregation of Revenue [Line Items]
Revenue																	90,290	89,787	86,590
Operating Segment | Real Estate Market | Revenue recognized when services are performed or assets are sold
Disaggregation of Revenue [Line Items]
Revenue																	88,755
Operating Segment | Real Estate Market | Revenue related to technology platforms and professional services
Disaggregation of Revenue [Line Items]
Revenue																	0
Operating Segment | Real Estate Market | Reimbursable expenses revenue
Disaggregation of Revenue [Line Items]
Revenue																	1,535
Operating Segment | Real Estate Market | Consumer Real Estate Solutions
Disaggregation of Revenue [Line Items]
Revenue																	8,595
Operating Segment | Real Estate Market | Consumer Real Estate Solutions | Revenue recognized when services are performed or assets are sold
Disaggregation of Revenue [Line Items]
Revenue																	8,593
Operating Segment | Real Estate Market | Consumer Real Estate Solutions | Revenue related to technology platforms and professional services
Disaggregation of Revenue [Line Items]
Revenue																	0
Operating Segment | Real Estate Market | Consumer Real Estate Solutions | Reimbursable expenses revenue
Disaggregation of Revenue [Line Items]
Revenue																	2
Operating Segment | Real Estate Market | Real Estate Investor Solutions
Disaggregation of Revenue [Line Items]
Revenue																	81,695
Operating Segment | Real Estate Market | Real Estate Investor Solutions | Revenue recognized when services are performed or assets are sold
Disaggregation of Revenue [Line Items]
Revenue																	80,162
Operating Segment | Real Estate Market | Real Estate Investor Solutions | Revenue related to technology platforms and professional services
Disaggregation of Revenue [Line Items]
Revenue																	0
Operating Segment | Real Estate Market | Real Estate Investor Solutions | Reimbursable expenses revenue
Disaggregation of Revenue [Line Items]
Revenue																	1,533
Other Businesses, Corporate and Eliminations
Disaggregation of Revenue [Line Items]
Revenue																	61,007	$ 58,742	$ 83,389
Other Businesses, Corporate and Eliminations | Revenue recognized when services are performed or assets are sold
Disaggregation of Revenue [Line Items]
Revenue																	55,226
Other Businesses, Corporate and Eliminations | Revenue related to technology platforms and professional services
Disaggregation of Revenue [Line Items]
Revenue																	5,733
Other Businesses, Corporate and Eliminations | Reimbursable expenses revenue
Disaggregation of Revenue [Line Items]
Revenue																	$ 48

[1] Effective January 1, 2018, the Company adopted Accounting Standards Update No. 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities, which requires certain equity investments to be measured at fair value with changes in fair value recognized in net income. Previously, changes in the fair value of the Company’s available for sale securities were included in comprehensive income. During the three months ended March 31, 2018, June 30, 2018, September 30, 2018 and December 31, 2018, we recognized unrealized (losses) gains from our investment in RESI common shares of $(7.5) million, $1.5 million, $1.8 million and $(8.8) million, respectively. See Note 6.

[2] In April 2018, Altisource entered into the Credit Agreement, pursuant to which, among other things, Altisource borrowed $412.0 million in the form of Term B Loans. Proceeds from the Term B Loans were used to repay the Company’s prior senior secured term loan. In connection with the refinancing, we recognized a loss of $4.4 million from the write-off of the unamortized debt issuance costs and debt discount in the second quarter of 2018. See Note 14.

[3] In August 2018, we initiated Project Catalyst, a restructuring plan intended to optimize our operations and reduce costs to align our cost structure with our anticipated revenues and improve our operating margins. During the three months ended September 30, 2018 and December 31, 2018, we incurred $3.4 million and $8.1 million, respectively, of severance costs, facility shut-down costs and professional services fees related to the restructuring plan. See Note 24.

[4] In August 2018, we sold our rental property management business to RESI for total transaction proceeds of $18.0 million, $15.0 million of which was received on the closing date of August 8, 2018 and $3.0 million of which will be received on the earlier of a RESI change of control or August 8, 2023. We recognized a $13.7 million pretax gain on the sale of this business during the third quarter of 2018. See Note 4.

[5] In November 2018, the Company announced its plans to sell its BRS Inventory and discontinue the Company’s BRS business. The Company recorded a write-off of goodwill related to its plan to discontinue the BRS business of $2.6 million during the three months ended December 31, 2018. See Notes 9 and 11.

[6] In connection with a United States Supreme Court decision in June 2018, the Company is analyzing its services for potential exposure to sales tax in various jurisdictions in the United States and believes that the Company has a related estimated probable loss of $6.2 million. The Company recognized $5.9 million and $0.4 million during the three months ended September 30, 2018 and December 31, 2018, respectively. See Note 25.

[7] The sum of quarterly amounts, including per share amounts, may not equal amounts reported for year-to-date periods. This is due to the effects of rounding and changes in the number of weighted average shares outstanding for each period.

[8] During the three months ended December, 31, 2017, the Company recognized net tax benefits of $284.1 million. On December 27, 2017, two of the Company’s wholly-owned subsidiaries, Altisource Solutions S.à r.l. and Altisource Holdings S.à r.l., merged, with Altisource Holdings S.à r.l. as the surviving entity. For Luxembourg tax purposes, the merger was recognized at fair value and generated an NOL of $1.3 billion and a deferred tax asset, net of valuation allowance, of $300.9 million. This deferred tax benefit was partially offset by $6.3 million of income tax from changes in U.S. and Luxembourg income tax rates and a $10.5 million increase in certain foreign income tax reserves (and related interest). See Note 22.