FAIR VALUES OF FINANCIAL INSTRUMENTS - Reconciliation of Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Total gains or losses (realized/unrealized):
MSRs sold	$ 39,186	$ 3
Discontinued Operations, Disposed of by Sale | Banc Home Loan
Total gains or losses (realized/unrealized):
Servicing rights carried at fair value	0	22,300	$ 37,681	$ 23,000
MSRs sold	37,772
Mortgage servicing rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	76,121	49,939
Transfers in and (out) of Level 3	0	0
Total gains or losses (realized/unrealized):
Included in earnings—fair value adjustment	(44)	(8,201)
Additions	7,801	8,582
Sales, paydowns, and other	(41,045)	(1,950)
Balance at end of period	42,833	48,370
Agency mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	58,260	18,291
Transfers in and (out) of Level 3	0	0
Total gains or losses (realized/unrealized):
Included in earnings—fair value adjustment	9	47
Additions	17,296	9,826
Sales, paydowns, and other	(8,864)	(1,584)
Balance at end of period	$ 66,701	$ 26,580