INVESTMENT SECURITIES (Tables)

12 Months Ended

Dec. 31, 2018

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:



($ in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
December 31, 2018
Securities available-for-sale:
SBA loan pool securities	$	911	$	—	$	(1	)	$	910
U.S. government agency and U.S. government sponsored enterprise residential mortgage-backed securities	461,987		—		(24,545		)	437,442
Non-agency residential mortgage-backed securities	418		9		—			427
Non-agency commercial mortgage-backed securities	132,199		—		—			132,199
Collateralized loan obligations	1,431,171		141		(9,790		)	1,421,522
Total securities available-for-sale	$	2,026,686	$	150	$	(34,336	)	$	1,992,500
December 31, 2017
Securities available-for-sale:
SBA loan pool securities	$	1,056	$	2	$	—		$	1,058
U.S. government agency and U.S. government sponsored enterprise residential mortgage-backed securities	492,255		10		(15,336		)	476,929
Non-agency residential mortgage-backed securities	741		16		(1		)	756
Non-agency commercial mortgage-backed securities	305,172		5,339		—			310,511
Collateralized loan obligations	1,691,455		11,129		(266		)	1,702,318
Corporate debt securities	76,714		7,183		—			83,897
Total securities available-for-sale	$	2,567,393	$	23,679	$	(15,603	)	$	2,575,469

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,
($ in thousands)	2018		2017		2016
Gross realized gains on sales and calls of securities available-for-sale	$	5,532	$	14,768	$	30,919
Gross realized losses on sales and calls of securities available-for-sale	—		—		(1,514		)
Net realized gains on sales and calls of securities available-for-sale	$	5,532	$	14,768	$	29,405
Proceeds from sales and calls of securities available-for-sale	$	1,025,471	$	1,500,459	$	4,148,003

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
($ in thousands)	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
December 31, 2018
Securities available-for-sale:
SBA loan pool securities	$	—	$	—		$	910	$	(1	)	$	910	$	(1	)
U.S. government agency and U.S. government sponsored enterprise residential mortgage-backed securities	$	13,494	$	(133	)	$	423,916	$	(24,412	)	$	437,410	$	(24,545	)
Non-agency residential mortgage-backed securities	90		—			16		—			106		—
Collateralized loan obligations	1,364,317		(9,480		)	32,790		(310		)	1,397,107		(9,790		)
Total securities available-for-sale	$	1,377,901	$	(9,613	)	$	457,632	$	(24,723	)	$	1,835,533	$	(34,336	)
December 31, 2017
Securities available-for-sale:
U.S. government agency and U.S. government sponsored enterprise residential mortgage-backed securities	4,880		(35		)	470,092		(15,301		)	474,972		(15,336		)
Non-agency residential mortgage-backed securities	—		—			148		(1		)	148		(1		)
Collateralized loan obligations	104,334		(266		)	—		—			104,334		(266		)
Total securities available-for-sale	$	109,214	$	(301	)	$	470,240	$	(15,302	)	$	579,454	$	(15,603	)

Composition, Repricing and Yield Information of Investment Securities

The following table presents the composition and the repricing and yield information of the investment securities portfolio as of December 31, 2018:



	One year or less				More than One Year through Five Years				More than Five Years through Ten Years				More than Ten Years				Total
($ in thousands)	Fair Value		Weighted-Average Yield		Fair Value		Weighted-Average Yield		Fair Value		Weighted-Average Yield		Fair Value		Weighted-Average Yield		Fair Value		Weighted-Average Yield
Securities available-for-sale:
SBA loan pool securities	$	—	—	%	$	—	—	%	$	—	—	%	$	910	2.84	%	$	910	2.84	%
U.S. government agency and U.S. government sponsored enterprise residential mortgage-backed securities	279		2.95	%	3,460		3.32	%	—		—	%	433,703		3.23	%	437,442		3.23	%
Non-agency residential mortgage-backed securities	83		3.96	%	—		—	%	—		—	%	344		5.47	%	427		5.18	%
Non-agency commercial mortgage-backed securities	—		—	%	—		—	%	132,199		3.75	%	—		—	%	132,199		3.75	%
Collateralized loan obligations	1,421,522		4.44	%	—		—	%	—		—	%	—		—	%	1,421,522		4.44	%
Total securities available-for-sale	$	1,421,884	4.44	%	$	3,460	3.32	%	$	132,199	3.75	%	$	434,957	3.23	%	$	1,992,500	4.13	%