GOODWILL AND INTANGIBLE ASSETS, NET - Goodwill (Details) - USD ($)			3 Months Ended	12 Months Ended
		Oct. 09, 2015	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Sep. 30, 2016	Jul. 29, 2016	Jun. 30, 2016
Goodwill
Business combination, consideration transferred				$ 0
Goodwill [Roll Forward]
Balance at the beginning of the period				86,283,000	$ 82,801,000
Balance at the end of the period			$ 82,801,000	86,283,000	86,283,000	$ 82,801,000
Balance at the end of the period			82,801,000	86,283,000	82,801,000	82,801,000
Goodwill impairment			55,700,000	0	0	55,700,000
Mortgage Market
Goodwill [Roll Forward]
Balance at the beginning of the period				73,259,000	69,827,000
Balance at the end of the period			69,827,000	73,259,000	73,259,000	69,827,000
Balance at the end of the period			69,827,000	73,259,000	69,827,000	69,827,000
Goodwill impairment			55,700,000
Real Estate Market
Goodwill [Roll Forward]
Balance at the beginning of the period				10,056,000	10,006,000
Balance at the end of the period			10,006,000	10,056,000	10,056,000	10,006,000
Balance at the end of the period			10,006,000	10,056,000	10,006,000	10,006,000
Other Businesses, Corporate and Eliminations
Goodwill [Roll Forward]
Balance at the beginning of the period				2,968,000	2,968,000
Balance at the end of the period			2,968,000	2,968,000	2,968,000	2,968,000
Balance at the end of the period			$ 2,968,000	$ 2,968,000	2,968,000	$ 2,968,000
CastleLine
Goodwill [Roll Forward]
Goodwill, purchase price allocation adjustment	[1]				(1,395,000)
Balance at the end of the period									$ 26,730,000
CastleLine | Mortgage Market
Goodwill [Roll Forward]
Goodwill, purchase price allocation adjustment	[1]				(1,395,000)
CastleLine | Real Estate Market
Goodwill [Roll Forward]
Goodwill, purchase price allocation adjustment	[1]				0
CastleLine | Other Businesses, Corporate and Eliminations
Goodwill [Roll Forward]
Goodwill, purchase price allocation adjustment	[1]				0
RentRange, Investability and Onit Solutions
Goodwill
Business combination, consideration transferred		$ 24,800,000
Goodwill [Roll Forward]
Goodwill, purchase price allocation adjustment	[2]				50,000
Balance at the end of the period							$ 19,615,000
RentRange, Investability and Onit Solutions | Mortgage Market
Goodwill [Roll Forward]
Goodwill, purchase price allocation adjustment	[2]				0
RentRange, Investability and Onit Solutions | Real Estate Market
Goodwill [Roll Forward]
Goodwill, purchase price allocation adjustment	[2]				50,000
RentRange, Investability and Onit Solutions | Other Businesses, Corporate and Eliminations
Goodwill [Roll Forward]
Goodwill, purchase price allocation adjustment	[2]				0
Granite
Goodwill [Roll Forward]
Goodwill, acquired during the period					4,827,000
Balance at the end of the period								$ 4,827,000
Granite | Mortgage Market
Goodwill [Roll Forward]
Goodwill, acquired during the period					4,827,000
Granite | Real Estate Market
Goodwill [Roll Forward]
Goodwill, acquired during the period					0
Granite | Other Businesses, Corporate and Eliminations
Goodwill [Roll Forward]
Goodwill, acquired during the period					$ 0

[1] During the second quarter of 2016, goodwill was revised to reflect a purchase accounting measurement period adjustment related to the CastleLine acquisition. See Note 5.

[2] During the third quarter of 2016, goodwill was revised to reflect a purchase accounting measurement period adjustment related to the RentRange and Investability acquisition. See Note 5.