INVESTMENT SECURITIES - Summary of Amortized Cost and Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Held-to-maturity
Amortized Cost	$ 962,203	$ 0
Gross Unrealized Gains	296
Gross Unrealized Losses	(30,214)
Securities held-to-maturity	932,285	0
Available-for-sale
Amortized Cost	838,768	344,878
Gross Unrealized Gains	198	1,435
Gross Unrealized Losses	(5,370)	(618)
Fair Value	833,596	345,695
SBA loan pool securities
Available-for-sale
Amortized Cost	1,485	1,697
Gross Unrealized Gains	19	18
Gross Unrealized Losses	0	0
Fair Value	1,504	1,715
U.S. government-sponsored entities and agency securities
Available-for-sale
Amortized Cost		1,940
Gross Unrealized Gains		42
Gross Unrealized Losses		0
Fair Value		1,982
Private label residential mortgage-backed securities
Available-for-sale
Amortized Cost	1,755	3,169
Gross Unrealized Gains	14	12
Gross Unrealized Losses	(1)	(13)
Fair Value	1,768	3,168
Corporate bonds
Available-for-sale
Amortized Cost	26,657
Gross Unrealized Gains	0
Gross Unrealized Losses	(505)
Fair Value	26,152
Collateralized loan obligations
Available-for-sale
Amortized Cost	111,719
Gross Unrealized Gains	31
Gross Unrealized Losses	(282)
Fair Value	111,468
Agency mortgage-backed securities
Available-for-sale
Amortized Cost	697,152	338,072
Gross Unrealized Gains	134	1,363
Gross Unrealized Losses	(4,582)	(605)
Fair Value	692,704	$ 338,830
Corporate bonds
Held-to-maturity
Amortized Cost	239,274
Gross Unrealized Gains	255
Gross Unrealized Losses	(20,946)
Securities held-to-maturity	218,583
Collateralized loan obligations
Held-to-maturity
Amortized Cost	416,284
Gross Unrealized Gains	0
Gross Unrealized Losses	(5,077)
Securities held-to-maturity	411,207
Commercial mortgage-backed securities
Held-to-maturity
Amortized Cost	306,645
Gross Unrealized Gains	41
Gross Unrealized Losses	(4,191)
Securities held-to-maturity	$ 302,495

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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