ACQUISITIONS - RentRange, Investability and Onit Solutions (Details) - USD ($) shares in Thousands		12 Months Ended
	Oct. 09, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Sep. 30, 2016
Acquisitions
Business combination, consideration transferred		$ 0
Value of common stock paid at acquisition		0	$ 0	$ 21,733,000
Goodwill		$ 86,283,000	$ 86,283,000	$ 82,801,000
RentRange, Investability and Onit Solutions
Acquisitions
Business combination, consideration transferred	$ 24,800,000
Cash paid at closing	$ 17,500,000
Contingent consideration arrangements, payment period	4 years
Number of shares exchanged for acquisition, no longer restricted (in shares)		14	55
Cash					$ 3,000
Accounts receivable, net					169,000
Premises and equipment, net					1,404,000
Other assets					3,000
Trademarks and trade names					1,205,000
Databases/other					1,945,000
Non-compete agreements					330,000
Customer relationships					255,000
Goodwill					19,615,000
Assets acquired					24,929,000
Accounts payable and accrued expenses					(345,000)
Purchase price					24,584,000
RentRange, Investability and Onit Solutions | Initial purchase price allocation
Acquisitions
Cash	$ 3,000
Accounts receivable, net	245,000
Premises and equipment, net	2,471,000
Other assets	199,000
Trademarks and trade names	1,205,000
Databases/other	910,000
Non-compete agreements	330,000
Customer relationships	255,000
Goodwill	19,565,000
Assets acquired	25,183,000
Accounts payable and accrued expenses	(391,000)
Purchase price	$ 24,792,000
RentRange, Investability and Onit Solutions | Adjustments
Acquisitions
Cash					0
Accounts receivable, net					(76,000)
Premises and equipment, net					(1,067,000)
Other assets					(196,000)
Trademarks and trade names					0
Databases/other					1,035,000
Non-compete agreements					0
Customer relationships					0
Goodwill					50,000
Assets acquired					(254,000)
Accounts payable and accrued expenses					46,000
Purchase price					$ (208,000)
Restricted Stock Units (RSUs) | RentRange, Investability and Onit Solutions
Acquisitions
Number of shares exchanged for acquisition (in shares)	247
Value of common stock paid at acquisition	$ 7,300,000
Shares exchanged for acquisition, number of shares repurchased		170