FAIR VALUE MEASUREMENTS - Schedule of Fair Value of Derivative Instruments and Loans Held for Sale (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2017	Dec. 31, 2016
Derivative notional amount and balance sheet location
Estimated Gain on Sale	$ 44,539	$ 62,863
Total Fair Value Adjustment	44,539	62,863
Derivative assets	43,853	61,824
Derivative Liabilities	(175)	(4,396)
Fair Value Adjustment To Loans Held for Sale	861	5,435
Loans Held for Sale
Derivative notional amount and balance sheet location
Notional or Principal Amount	3,274,900	1,852,923
Estimated Gain on Sale	25,247	47,019
Interest Rate Movement	(24,386)	(41,584)
Total Fair Value Adjustment	861	5,435
Fair Value Adjustment To Loans Held for Sale	861	5,435
Rate Lock Commitments
Derivative notional amount and balance sheet location
Notional or Principal Amount	688,375	395,462
Estimated Gain on Sale	19,292	15,844
Interest Rate Movement	(4,987)	(2,275)
Total Fair Value Adjustment	14,305	13,569
Derivative assets	14,305	14,482
Derivative Liabilities		(913)
Forward Sale Contracts
Derivative notional amount and balance sheet location
Notional or Principal Amount	3,963,275	2,248,385
Interest Rate Movement	29,373	43,859
Total Fair Value Adjustment	29,373	43,859
Derivative assets	29,548	47,342
Derivative Liabilities	$ (175)	$ (3,483)

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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Amount of fair value adjustment related to both assumed gains and interest rate movements.

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