INVESTMENT SECURITIES (Tables)

12 Months Ended

Dec. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Summary of Amortized Cost and Fair Value of Investment Securities

The following table presents the amortized cost and fair value of the investment securities portfolio as of the dates indicated:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(In thousands)
December 31, 2016
Held-to-maturity
Corporate bonds	$	240,090	$	13,032	$	(91	)	$	253,031
Collateralized loan obligations	338,226		1,461		(61		)	339,626
Commercial mortgage-backed securities	305,918		2,949		(1,781		)	307,086
Total securities held-to-maturity	$	884,234	$	17,442	$	(1,933	)	$	899,743
Available-for-sale
SBA loan pool securities	$	1,221	$	—	$	—		$	1,221
Private label residential mortgage-backed securities	121,397		18		(4,238		)	117,177
Corporate bonds	48,574		482		(108		)	48,948
Collateralized loan obligations	1,395,094		12,449		(674		)	1,406,869
Agency mortgage-backed securities	830,682		9		(23,418		)	807,273
Total securities available-for-sale	$	2,396,968	$	12,958	$	(28,438	)	$	2,381,488
December 31, 2015
Held-to-maturity
Corporate bonds	$	239,274	$	255	$	(20,946	)	$	218,583
Collateralized loan obligations	416,284		—		(5,077		)	411,207
Commercial mortgage-backed securities	306,645		41		(4,191		)	302,495
Total securities held-to-maturity	$	962,203	$	296	$	(30,214	)	$	932,285
Available-for-sale
SBA loan pool securities	$	1,485	$	19	$	—		$	1,504
Private label residential mortgage-backed securities	1,755		14		(1		)	1,768
Corporate bonds	26,657		—		(505		)	26,152
Collateralized loan obligations	111,719		31		(282		)	111,468
Agency mortgage-backed securities	697,152		134		(4,582		)	692,704
Total securities available-for-sale	$	838,768	$	198	$	(5,370	)	$	833,596

Summary of Amortized Cost and Fair Value of Available-for-Sale Investment Securities Portfolio

The following table presents amortized cost and fair value of the held-to-maturity and available-for-sale investment securities portfolio by expected maturity. In the case of mortgage-backed securities, collateralized loan obligations, and SBA loan pool securities, expected maturities may differ from contractual maturities because borrowers generally have the right to call or prepay obligations with or without call or prepayment penalties. For that reason, mortgage-backed securities, collateralized loan obligations, and SBA loan pool securities are not included in the maturity categories.

	December 31, 2016
	Held-to-Maturity				Available-for-Sale
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
	(In thousands)
Maturity:
Within one year	$	—	$	—	$	—	$	—
One to five years	15,000		15,084		31,500		31,910
Five to ten years	225,090		237,947		17,074		17,038
Greater than ten years	—		—		—		—
Collateralized loan obligations, SBA loan pool, private label residential mortgage-backed, commercial mortgage-backed, and agency mortgage-backed securities	644,144		646,712		2,348,394		2,332,540
Total	$	884,234	$	899,743	$	2,396,968	$	2,381,488

Proceeds from Sales and Calls of Securities and Associated Gross Gains and Losses

The following table presents proceeds from sales and calls of securities available-for-sale and the associated gross gains and losses realized through earnings upon the sales and calls of securities available-for-sale for the periods indicated:

	Year Ended December 31,
	2016			2015			2014
	(In thousands)
Gross realized gains on sales and calls of securities available-for-sale	$	30,919		$	3,260		$	1,221
Gross realized losses on sales and calls of securities available-for-sale	(1,514		)	(2		)	(38		)
Net realized gains on sales and calls of securities available-for-sale	$	29,405		$	3,258		$	1,183
Proceeds from sales and calls of securities available-for-sale	$	4,148,003		$	989,786		$	111,764
Tax expense on sales and calls of securities available-for-sale	$	12,218		$	1,368		$	498

Summary of Investment Securities with Unrealized Losses

The following table summarizes the investment securities with unrealized losses by security type and length of time in a continuous unrealized loss position as of the dates indicated:

	Less Than 12 Months					12 Months or Longer					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
	(In thousands)
December 31, 2016
Held-to-maturity
Corporate bonds	$	9,907	$	(91	)	$	—	$	—		$	9,907	$	(91	)
Collateralized loan obligations	10,056		(6		)	56,095		(55		)	66,151		(61		)
Commercial mortgage-backed securities	60,221		(1,781		)	—		—			60,221		(1,781		)
Total securities held-to-maturity	$	80,184	$	(1,878	)	$	56,095	$	(55	)	$	136,279	$	(1,933	)
Available-for-sale
SBA loan pool securities	$	1,221	$	—		$	—	$	—		$	1,221	$	—
Private label residential mortgage-backed securities	$	116,216	$	(4,238	)	$	230	$	—		$	116,446	$	(4,238	)
Corporate bonds	—		—			3,530		(108		)	3,530		(108		)
Collateralized loan obligations	187,592		(674		)	—		—			187,592		(674		)
Agency mortgage-backed securities	805,803		(23,410		)	760		(8		)	806,563		(23,418		)
Total securities available-for-sale	$	1,110,832	$	(28,322	)	$	4,520	$	(116	)	$	1,115,352	$	(28,438	)
December 31, 2015
Held-to-maturity
Corporate bonds	$	190,332	$	(20,946	)	$	—	$	—		$	190,332	$	(20,946	)
Collateralized loan obligations	411,207		(5,077		)	—		—			411,207		(5,077		)
Commercial mortgage-backed securities	277,351		(4,191		)	—		—			277,351		(4,191		)
Total securities held-to-maturity	$	878,890	$	(30,214	)	$	—	$	—		$	878,890	$	(30,214	)
Available-for-sale
Private label residential mortgage-backed securities	$	—	$	—		$	403	$	(1	)	$	403	$	(1	)
Corporate bonds	26,152		(505		)	—		—			26,152		(505		)
Collateralized loan obligations	72,204		(282		)	—		—			72,204		(282		)
Agency mortgage-backed securities	599,814		(4,459		)	6,832		(123		)	606,646		(4,582		)
Total securities available-for-sale	$	698,170	$	(5,246	)	$	7,235	$	(124	)	$	705,405	$	(5,370	)