EARNINGS PER SHARE - Schedule of Calculation of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Denominator:
Weighted average number of shares of Class A common stock outstanding (in shares)	85,135,685	62,148,362	79,416,957	60,976,046
Basic net income (loss) per share of Class A common stock (in dollars per share)	$ 0.28	$ 0.44	$ 0.61	$ 0.41
Denominator:
Weighted average number of shares of Class A common stock outstanding (in shares)	85,135,685	62,148,362	79,416,957	60,976,046
Diluted weighted average number of shares of Class A common stock outstanding (in shares)	85,476,266	63,347,690	109,857,679	61,875,010
Diluted net income per share of Class A common stock (in dollars per share)	$ 0.28	$ 0.44	$ 0.59	$ 0.40
Class A common stock
Numerator:
Net income (loss) attributable to Class A common shareholders	$ 24,039	$ 27,608	$ 48,172	$ 24,871
Denominator:
Weighted average number of shares of Class A common stock outstanding (in shares)	85,135,685	62,148,362	79,416,957	60,976,046
Basic net income (loss) per share of Class A common stock (in dollars per share)	$ 0.28	$ 0.44	$ 0.61	$ 0.41
Numerator:
Net income (loss) attributable to Class A common shareholders	$ 24,039	$ 27,608	$ 48,172	$ 24,871
Amounts attributable to operating partnership’s share of Ladder Capital Corp net income (loss)	0	0	15,210	0
Additional corporate tax (expense) benefit	0	0	1,893	0
Diluted Net income (loss) available for Class A common shareholders	$ 24,039	$ 27,608	$ 65,275	$ 24,871
Denominator:
Weighted average number of shares of Class A common stock outstanding (in shares)	85,135,685	62,148,362	79,416,957	60,976,046
Shares issuable relating to converted Class B common shareholders (in shares)	0	0	30,211,137	0
Incremental shares of unvested Class A restricted stock (in shares)	340,581	1,199,328	229,585	898,964
Diluted weighted average number of shares of Class A common stock outstanding (in shares)	85,476,266	63,347,690	109,857,679	61,875,010
Diluted net income per share of Class A common stock (in dollars per share)	$ 0.28	$ 0.44	$ 0.59	$ 0.40