EARNINGS PER SHARE - Schedule of Calculation of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Denominator:
Weighted average number of shares of Class A common stock outstanding (in shares)	105,511,385	96,810,266	104,888,925	96,003,151
Basic net income (loss) per share of Class A common stock (in dollars per share)	$ 0.31	$ 0.40	$ 0.52	$ 0.93
Denominator:
Weighted average number of shares of Class A common stock outstanding (in shares)	105,511,385	96,810,266	104,888,925	96,003,151
Diluted weighted average number of shares of Class A common stock outstanding (in shares)	105,892,420	97,165,899	105,742,589	96,276,824
Diluted net income (loss) per share of Class A common stock (in dollars per share)	$ 0.30	$ 0.40	$ 0.51	$ 0.93
Class A Common Stock
Numerator:
Net income (loss) attributable to Class A common shareholders	$ 32,244	$ 38,406	$ 54,419	$ 89,281
Denominator:
Weighted average number of shares of Class A common stock outstanding (in shares)	105,511,385	96,810,266	104,888,925	96,003,151
Basic net income (loss) per share of Class A common stock (in dollars per share)	$ 0.31	$ 0.40	$ 0.52	$ 0.93
Numerator:
Net income (loss) attributable to Class A common shareholders	$ 32,244	$ 38,406	$ 54,419	$ 89,281
Amounts attributable to operating partnership’s share of Ladder Capital Corp net income (loss)	0	0	0	0
Additional corporate tax (expense) benefit	0	0	0	0
Diluted Net income (loss) available for Class A common shareholders	$ 32,244	$ 38,406	$ 54,419	$ 89,281
Denominator:
Weighted average number of shares of Class A common stock outstanding (in shares)	105,511,385	96,810,266	104,888,925	96,003,151
Shares issuable relating to converted Class B common shareholders (in shares)	0	0	0	0
Incremental shares of unvested Class A restricted stock (in shares)	381,035	355,633	853,664	273,673
Diluted weighted average number of shares of Class A common stock outstanding (in shares)	105,892,420	97,165,899	105,742,589	96,276,824
Diluted net income (loss) per share of Class A common stock (in dollars per share)	$ 0.30	$ 0.40	$ 0.51	$ 0.93