GAINS FROM MORTGAGE BANKING ACTIVITIES (Details) - USD ($) $ in Thousands	3 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, 2016	Dec. 31, 2015	Dec. 31, 2014
GAINS FROM MORTGAGE BANKING ACTIVITIES
Contractual loan origination related fees, net									$ 174,360	$ 156,835	$ 125,468
Fair value of expected net future cash flows from servicing recognized at commitment									205,311	142,420	103,410
Fair value of expected guaranty obligation recognized at commitment									(12,486)	(8,789)	(6,895)
Total gains from mortgage banking activities	$ 117,779	$ 100,630	$ 102,453	$ 46,323	$ 76,986	$ 70,810	$ 69,950	$ 72,720	$ 367,185	$ 290,466	$ 221,983