STOCK BASED AND OTHER COMPENSATION PLANS - Stock Based Compensation Plans Summary (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity based compensation expense	$ 3,469	$ 2,105	$ 14,761	$ 4,505
Ladder Capital Corp Deferred Compensation Plan	0	236	0	919
Bonus Expense	7,717	7,782	14,501	17,562
Other Employee/Director Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity based compensation expense	4	12	16	33
Phantom Equity Investment Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity based compensation expense	(98)	0	704	0
Annual Incentive Awards Granted in 2015 with Respect to 2014 Performance | 2014 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity based compensation expense	0	0	0	172
Annual Incentive Awards Granted in 2016 with Respect to 2015 Performance | 2014 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity based compensation expense	0	325	131	647
Annual Incentive Awards Granted in 2017 With Respect to 2016 Performance | 2014 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity based compensation expense	282	509	676	1,131
Other 2017 Restricted Stock Awards | 2014 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity based compensation expense	25	76	76	181
Annual Incentive Awards Granted in 2017 With Respect to 2017 Performance | 2014 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity based compensation expense	580	1,087	1,365	2,202
2018 Restricted Stock Awards | 2014 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity based compensation expense	0	93	32	136
Other 2018 Restricted Stock Awards | 2014 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity based compensation expense	10	3	21	3
Annual Incentive Awards Granted in 2019 with Respect to 2018 Performance | 2014 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity based compensation expense	2,481	0	12,295	0
Other 2019 Restricted Stock Awards | 2014 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity based compensation expense	$ 87	$ 0	$ 149	$ 0