DEBT OBLIGATIONS, NET - Additional Information (Details)								12 Months Ended
	Aug. 03, 2016 USD ($) Extension	Apr. 19, 2016 Extension	Mar. 21, 2016 USD ($)	Oct. 25, 2015 USD ($) Extension	Oct. 31, 2014	Feb. 11, 2014 USD ($) Extension	Jan. 24, 2013 USD ($) Financing_Counterparty	Dec. 31, 2016 USD ($) counterparty agreement Extension	Dec. 31, 2015 USD ($) agreement Extension	Dec. 31, 2014 USD ($) agreement	Feb. 24, 2017 USD ($)	Jul. 01, 2016 USD ($)	Jun. 28, 2016 USD ($)	Feb. 19, 2016	Aug. 14, 2015 USD ($) Extension	Apr. 10, 2015 USD ($) Extension	Feb. 19, 2015 Extension	Sep. 19, 2012 USD ($)
Committed Loan and Securities Repurchase Facilities
Debt obligations outstanding								$ 1,107,185,000	$ 1,260,755,000
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Contractual payments under current maturities subject to extensions								1,759,701,000
Restricted equity from payment as dividend								899,400,000
Mortgage Loans on Real Estate [Abstract]
Amortization of premiums								$ (894,000)	(902,000)	$ (629,000)
Borrowings from Federal Home Loan Bank (FHLB) [Abstract]
Percent of FHLB advances to total debt obligations outstanding								42.10%
Tuebor
Borrowings from Federal Home Loan Bank (FHLB) [Abstract]
Amount restricted from transfer								$ 349,900,000
Revolving credit facility | One-Month LIBOR
Committed Loan and Securities Repurchase Facilities
Number of extension maturity periods | Extension						2
Length of extension options						12 months
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Basis spread on variable rate (as a percent)						3.50%
Committed amount on credit agreement						$ 143,000,000.0
Debt borrowings term						3 years
Letters of credit
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Committed amount on credit agreement						$ 25,000,000.0
Term master repurchase agreement
Committed Loan and Securities Repurchase Facilities
Committed amount on master repurchase agreement								$ 400,000,000.0
Number of extension maturity periods | Extension																	1
Committed Loan repurchase facility
Committed Loan and Securities Repurchase Facilities
Number of agreements | agreement								5
Committed amount on master repurchase agreement								$ 1,650,000,000	1,485,000,000
Debt obligations outstanding								567,163,000	704,149,000
Total Repurchase Facilities
Committed Loan and Securities Repurchase Facilities
Committed amount on master repurchase agreement								2,050,000,000	1,785,000,000
Debt obligations outstanding								$ 1,107,185,000	$ 1,260,755,000
Total Repurchase Facilities | Deutshe Bank, J.P. Morgan and Wells Fargo
Committed Loan and Securities Repurchase Facilities
Repurchase agreements, number of counterparties | counterparty								9
Excess collateral over amounts borrowed under repurchase agreements								$ 75,500,000
Ratio indebtedness over total equity (as a percent)								5.00%
Haircut on repurchase agreements (as a percent)								31.10%
Uncommitted securities Repurchase Facilities | Minimum
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Advance rates (as a percent)								70.00%
Uncommitted securities Repurchase Facilities | Maximum
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Advance rates (as a percent)								95.00%
Committed Loan Repurchase and Revolving Credit Facilities
Committed Loan and Securities Repurchase Facilities
Number of extension maturity periods | Extension								1
Length of additional extension maturity periods								1 year
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Contractual payments under current maturities subject to extensions								$ 1,500,000,000
10/30/2018 | Committed Loan repurchase facility
Committed Loan and Securities Repurchase Facilities
Committed amount on master repurchase agreement								$ 600,000,000
Number of extension maturity periods | Extension								3
Length of extension options								12 months	1 year
Debt obligations outstanding								$ 183,604,000
5/24/2017 | Committed Loan repurchase facility
Committed Loan and Securities Repurchase Facilities
Committed amount on master repurchase agreement								$ 450,000,000
Number of extension maturity periods | Extension		2						3
Length of extension options		1 year						12 months
Debt obligations outstanding								$ 184,158,000
4/9/2017 | Committed Loan repurchase facility
Committed Loan and Securities Repurchase Facilities
Committed amount on master repurchase agreement								$ 400,000,000								$ 400,000,000.0
Number of extension maturity periods | Extension								2
Length of extension options								364 days
Debt obligations outstanding								$ 100,979,000
6/28/2019 | Committed Loan repurchase facility
Committed Loan and Securities Repurchase Facilities
Committed amount on master repurchase agreement								100,000,000					$ 100,000,000.0
Debt obligations outstanding								27,132,000
8/2/2019 | Committed Loan repurchase facility
Committed Loan and Securities Repurchase Facilities
Committed amount on master repurchase agreement	$ 100,000,000.0							$ 100,000,000
Number of extension maturity periods | Extension	1							1
Length of extension options	12 months							12 months
Debt obligations outstanding								$ 71,290,000
Number of additional extension maturity periods | Extension	2							2
Length of additional extension maturity periods	6 months							6 months
7/1/2018 | Term master repurchase agreement
Committed Loan and Securities Repurchase Facilities
Committed amount on master repurchase agreement								$ 400,000,000				$ 400,000,000.0
Debt obligations outstanding								228,317,000
5/24/2016 | Committed Loan repurchase facility
Committed Loan and Securities Repurchase Facilities
Committed amount on master repurchase agreement									$ 450,000,000
Number of extension maturity periods | Extension									2
Length of extension options									12 months
Debt obligations outstanding									$ 269,779,000
4/10/2019 | Term master repurchase agreement
Committed Loan and Securities Repurchase Facilities
Number of extension maturity periods | Extension																1
10/30/2016 | Committed Loan repurchase facility
Committed Loan and Securities Repurchase Facilities
Committed amount on master repurchase agreement									$ 600,000,000						$ 600,000,000.0
Number of extension maturity periods | Extension									2						1
Length of extension options									12 months
Debt obligations outstanding									$ 229,533,000
10/24/2016 | Committed Loan repurchase facility
Committed Loan and Securities Repurchase Facilities
Committed amount on master repurchase agreement				$ 35,000,000.0					$ 35,000,000
Number of extension maturity periods | Extension				2					2
Length of extension options				6 months					6 months
Debt obligations outstanding									$ 575,000
Committed amount or master repurchase facility terminated	$ 35,000,000.0
1/2016 | Uncommitted securities Repurchase Facilities
Committed Loan and Securities Repurchase Facilities
Debt obligations outstanding									394,719,000
Credit and Security Agreement | One-Month LIBOR
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Basis spread on variable rate (as a percent)					1.85%
Credit Agreement and Revolving Credit Facility
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Unamortized debt issuance costs								$ 4,900,000	$ 3,400,000	$ 4,000,000.0
Credit Agreement
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Committed amount on credit agreement							$ 50,000,000.0
Number of multiple committed financing counterparties | Financing_Counterparty							1
Mortgage loan financing
Committed Loan and Securities Repurchase Facilities
Number of agreements | agreement								18	36	5
Mortgage Loans on Real Estate [Abstract]
Mortgage loan financing								$ 590,100,000	$ 544,700,000	$ 447,400,000
Net unamortized premiums								5,600,000	6,100,000	5,300,000
Amortization of premiums								900,000	900,000	$ 600,000
Pledged assets, real estate and lease intangibles, net								$ 757,500,000	$ 711,100,000
Mortgage loan financing | Minimum
Borrowings from Federal Home Loan Bank (FHLB) [Abstract]
Stated interest rate on debt instrument (as a percent)								4.25%
Mortgage loan financing | Maximum
Borrowings from Federal Home Loan Bank (FHLB) [Abstract]
Stated interest rate on debt instrument (as a percent)								6.75%
Borrowings from the Federal Home Loan Bank | Tuebor
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Debt borrowings term								7 years	8 years
Borrowings from Federal Home Loan Bank (FHLB) [Abstract]
Maximum advance limit			$ 2,900,000,000
FHLB borrowings outstanding								$ 1,700,000,000	$ 1,900,000,000
Additional committed term financing available from FHLB								$ 338,900,000	$ 380,400,000
Weighted average term								2 years 4 months 24 days	1 year 4 months 24 days
Weighted average interest rate								1.12%	0.84%
Maximum percent of FHLB advances to total assets														40.00%
Borrowings from the Federal Home Loan Bank | Tuebor | Ladder Capital Corp
Borrowings from Federal Home Loan Bank (FHLB) [Abstract]
Advance rates of total assets (as a percent)			40.00%
Advance rates of total equity (as a percent)			150.00%
Borrowings from the Federal Home Loan Bank | Tuebor | Minimum
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Advance rates (as a percent)								49.60%	58.70%
Borrowings from Federal Home Loan Bank (FHLB) [Abstract]
Stated interest rate on debt instrument (as a percent)								0.43%	0.28%
Borrowings from the Federal Home Loan Bank | Tuebor | Maximum
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Advance rates (as a percent)								95.20%	95.20%
Borrowings from Federal Home Loan Bank (FHLB) [Abstract]
Stated interest rate on debt instrument (as a percent)								2.74%	2.74%
Borrowings from the Federal Home Loan Bank | Tuebor | CMBS and U.S. Agency Securities
Borrowings from Federal Home Loan Bank (FHLB) [Abstract]
Collateral for debt instrument								$ 1,400,000,000	$ 1,700,000,000
Borrowings from the Federal Home Loan Bank | Tuebor | First mortgage commercial real estate loans
Borrowings from Federal Home Loan Bank (FHLB) [Abstract]
Collateral for debt instrument								724,000,000.0	$ 568,200,000
Senior Unsecured Notes | Senior Notes Due, 2017
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Debt instrument, aggregate amount								$ 297,700,000										$ 325,000,000.0
Borrowings from Federal Home Loan Bank (FHLB) [Abstract]
Stated interest rate on debt instrument (as a percent)																		7.375%
Senior Unsecured Notes | Senior Notes Due, 2017 | Scenario, Forecast
Borrowing Under Credit Facilties and Debt Issuance Costs [Abstract]
Debt instrument, aggregate amount											$ 291,500,000