EARNINGS PER SHARE - Schedule of Calculation of Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								11 Months Ended	12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator:
Net income (loss) attributable to Class A common shareholders	$ 41,856	$ 27,608	$ 2,802	$ (5,539)	$ 27,123	$ 3,313	$ 34,210	$ 9,175		$ 66,727	$ 73,821	$ 44,187
Denominator:
Weighted average number of shares of Class A common stock outstanding (in shares)									49,296,417	61,998,089	51,702,188	49,296,417
Basic net income (loss) per share of Class A common stock (in dollars per share)	$ 0.64	$ 0.44	$ 0.05	$ (0.09)	$ 0.51	$ 0.06	$ 0.68	$ 0.18		$ 1.08	$ 1.43	$ 0.90
Numerator:
Net income (loss) attributable to Class A common shareholders	$ 41,856	$ 27,608	$ 2,802	$ (5,539)	$ 27,123	$ 3,313	$ 34,210	$ 9,175		$ 66,727	$ 73,821	$ 44,187
Denominator:
Weighted average number of shares of Class A common stock outstanding (in shares)									49,296,417	61,998,089	51,702,188	49,296,417
Diluted weighted average number of shares of Class A common stock outstanding (in shares)									97,583,310	107,638,788	51,870,808	97,583,310
Diluted net income per share of Class A common stock (in dollars per share)	$ 0.63	$ 0.44	$ 0.05	$ (0.09)	$ 0.50	$ 0.06	$ 0.67	$ 0.15		$ 1.06	$ 1.42	$ 0.86
Class A common stock
Numerator:
Net income (loss) attributable to Class A common shareholders									$ 44,187	$ 66,727	$ 73,821	$ 44,187
Denominator:
Weighted average number of shares of Class A common stock outstanding (in shares)									49,296,417	61,998,089	51,702,188
Basic net income (loss) per share of Class A common stock (in dollars per share)									$ 0.90	$ 1.08	$ 1.43
Numerator:
Net income (loss) attributable to Class A common shareholders									$ 44,187	$ 66,727	$ 73,821	$ 44,187
Amounts attributable to operating partnership’s share of Ladder Capital Corp net income (loss)									66,437	47,130	0
Additional corporate tax (expense) benefit									(26,396)	299	0
Diluted Net income (loss) available for Class A common shareholders									$ 84,228	$ 114,156	$ 73,821
Denominator:
Weighted average number of shares of Class A common stock outstanding (in shares)									49,296,417	61,998,089	51,702,188
Shares issuable relating to converted Class B common shareholders (in shares)									48,145,875	45,118,668	0
Incremental shares of unvested Class A restricted stock (in shares)									141,018	522,031	168,620
Diluted weighted average number of shares of Class A common stock outstanding (in shares)									97,583,310	107,638,788	51,870,808
Diluted net income per share of Class A common stock (in dollars per share)									$ 0.86	$ 1.06	$ 1.42