Securities (Tables)

6 Months Ended

Jun. 30, 2015

Investments, Debt and Equity Securities [Abstract]

Schedule of Amortized Cost and Fair Value of Securities Available for Sale

The amortized cost and fair value of securities are as follows:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Securities Available for Sale
June 30, 2015
U.S. Treasury	$	29,670	$	258	$	—		$	29,928
U.S. government-sponsored entities		403,396		1,853		(1,173	)		404,076
Residential mortgage-backed securities:
Agency mortgage-backed securities		588,103		6,454		(801	)		593,756
Agency collateralized mortgage obligations		561,212		2,324		(7,939	)		555,597
Non-agency collateralized mortgage obligations		1,270		9		—			1,279
Commercial mortgage-backed securities		5,004		2		—			5,006
States of the U.S. and political subdivisions		11,138		359		(40	)		11,457
Other debt securities		16,671		312		(742	)		16,241
Total debt securities		1,616,464		11,571		(10,695	)		1,617,340
Equity securities		975		305		—			1,280
	$	1,617,439	$	11,876	$	(10,695	)	$	1,618,620

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
December 31, 2014
U.S. Treasury	$	29,604	$	78	$	—		$	29,682
U.S. government-sponsored entities		338,330		742		(1,939	)		337,133
Residential mortgage-backed securities:
Agency mortgage-backed securities		546,572		7,548		(35	)		554,085
Agency collateralized mortgage obligations		580,601		1,617		(9,047	)		573,171
Non-agency collateralized mortgage obligations		1,414		17		—			1,431
Commercial mortgage-backed securities		7,891		—		(11	)		7,880
States of the U.S. and political subdivisions		12,713		477		(32	)		13,158
Other debt securities		16,615		420		(857	)		16,178
Total debt securities		1,533,740		10,899		(11,921	)		1,532,718
Equity securities		1,031		316		—			1,347
	$	1,534,771	$	11,215	$	(11,921	)	$	1,534,065

Schedule of Amortized Cost and Fair Value of Securities Held to Maturity

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
December 31, 2014
U.S. Treasury	$	29,604	$	78	$	—		$	29,682
U.S. government-sponsored entities		338,330		742		(1,939	)		337,133
Residential mortgage-backed securities:
Agency mortgage-backed securities		546,572		7,548		(35	)		554,085
Agency collateralized mortgage obligations		580,601		1,617		(9,047	)		573,171
Non-agency collateralized mortgage obligations		1,414		17		—			1,431
Commercial mortgage-backed securities		7,891		—		(11	)		7,880
States of the U.S. and political subdivisions		12,713		477		(32	)		13,158
Other debt securities		16,615		420		(857	)		16,178
Total debt securities		1,533,740		10,899		(11,921	)		1,532,718
Equity securities		1,031		316		—			1,347
	$	1,534,771	$	11,215	$	(11,921	)	$	1,534,065
Securities Held to Maturity
June 30, 2015
U.S. Treasury	$	500	$	152	$	—		$	652
U.S. government-sponsored entities		146,561		1,054		(379	)		147,236
Residential mortgage-backed securities:
Agency mortgage-backed securities		670,817		12,981		(1,006	)		682,792
Agency collateralized mortgage obligations		484,832		2,351		(6,793	)		480,390
Non-agency collateralized mortgage obligations		3,375		14		(3	)		3,386
Commercial mortgage-backed securities		17,410		231		—			17,641
States of the U.S. and political subdivisions		194,565		1,936		(2,558	)		193,943
	$	1,518,060	$	18,719	$	(10,739	)	$	1,526,040
December 31, 2014
U.S. Treasury	$	502	$	168	$	—		$	670
U.S. government-sponsored entities		101,602		885		(524	)		101,963
Residential mortgage-backed securities:
Agency mortgage-backed securities		677,169		16,712		(346	)		693,535
Agency collateralized mortgage obligations		501,965		1,858		(7,329	)		496,494
Non-agency collateralized mortgage obligations		4,285		28		—			4,313
Commercial mortgage-backed securities		17,560		179		—			17,739
States of the U.S. and political subdivisions		150,272		3,315		(43	)		153,544
	$	1,453,355	$	23,145	$	(8,242	)	$	1,468,258

Gross Gains and Gross Losses Realized on Sales of Securities

Gross gains and gross losses were realized on securities as follows:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2015		2014		2015			2014
Gross gains	$	14	$	739	$	14		$	18,748
Gross losses		—		37		(9	)		(8,511	)
	$	14	$	776	$	5		$	10,237

Amortized Cost and Fair Value of Securities, by Contractual Maturities

As of June 30, 2015, the amortized cost and fair value of securities, by contractual maturities, were as follows:

	Available for Sale				Held to Maturity
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in one year or less	$	4,990	$	5,040	$	1,010	$	1,017
Due from one to five years		438,979		440,208		140,854		141,072
Due from five to ten years		10,014		10,304		72,031		73,550
Due after ten years		6,892		6,150		127,731		126,192
		460,875		461,702		341,626		341,831
Residential mortgage-backed securities:
Agency mortgage-backed securities		588,103		593,756		670,817		682,792
Agency collateralized mortgage obligations		561,212		555,597		484,832		480,390
Non-agency collateralized mortgage obligations		1,270		1,279		3,375		3,386
Commercial mortgage-backed securities		5,004		5,006		17,410		17,641
Equity securities		975		1,280		—		—
	$	1,617,439	$	1,618,620	$	1,518,060	$	1,526,040

Summaries of Fair Values and Unrealized Losses of Securities, Segregated by Length of Impairment

Following are summaries of the fair values and unrealized losses of securities, segregated by length of impairment:

	Less than 12 Months							12 Months or More							Total
	#		Fair Value		Unrealized Losses			#		Fair Value		Unrealized Losses			#		Fair Value		Unrealized Losses
Securities Available for Sale
June 30, 2015
U.S. government-sponsored entities		5	$	84,445	$	(571	)		5	$	55,389	$	(602	)		10	$	139,834	$	(1,173	)
Residential mortgage-backed securities:
Agency mortgage-backed securities		11		186,261		(801	)		—		—		—			11		186,261		(801	)
Agency collateralized mortgage obligations		6		104,538		(563	)		18		237,775		(7,376	)		24		342,313		(7,939	)
States of the U.S. and political subdivisions		1		2,079		(3	)		1		1,153		(37	)		2		3,232		(40	)
Other debt securities		—		—		—			4		6,150		(742	)		4		6,150		(742	)
		23	$	377,323	$	(1,938	)		28	$	300,467	$	(8,757	)		51	$	677,790	$	(10,695	)

	Less than 12 Months							12 Months or More							Total
	#		Fair Value		Unrealized Losses			#		Fair Value		Unrealized Losses			#		Fair Value		Unrealized Losses
December 31, 2014
U.S. government-sponsored entities		7	$	89,986	$	(275	)		7	$	99,326	$	(1,664	)		14	$	189,312	$	(1,939	)
Residential mortgage-backed securities:
Agency mortgage-backed securities		2		45,145		(35	)		—		—		—			2		45,145		(35	)
Agency collateralized mortgage obligations		9		166,908		(1,238	)		16		225,700		(7,809	)		25		392,608		(9,047	)
Commercial mortgage-backed securities		1		7,880		(11	)		—		—		—			1		7,880		(11	)
States of the U.S. and political subdivisions		—		—		—			1		1,159		(32	)		1		1,159		(32	)
Other debt securities		—		—		—			4		6,030		(857	)		4		6,030		(857	)
		19	$	309,919	$	(1,559	)		28	$	332,215	$	(10,362	)		47	$	642,134	$	(11,921	)
Securities Held to Maturity
June 30, 2015
U.S. government-sponsored entities		3	$	44,772	$	(227	)		1	$	14,849	$	(152	)		4	$	59,621	$	(379	)
Residential mortgage-backed securities:
Agency mortgage-backed securities		10		115,966		(974	)		1		1,127		(32	)		11		117,093		(1,006	)
Agency collateralized mortgage obligations		7		95,239		(884	)		14		176,572		(5,909	)		21		271,811		(6,793	)
Non-agency collateralized mortgage obligations		2		1,731		(3	)		—		—		—			2		1,731		(3	)
States of the U.S. and political subdivisions		45		83,795		(2,558	)		—		—		—			45		83,795		(2,558	)
		67	$	341,503	$	(4,646	)		16	$	192,548	$	(6,093	)		83	$	534,051	$	(10,739	)
December 31, 2014
U.S. government-sponsored entities		2	$	24,989	$	(40	)		2	$	29,516	$	(484	)		4	$	54,505	$	(524	)
Residential mortgage-backed securities:
Agency mortgage-backed securities		1		1,099		(1	)		4		45,042		(345	)		5		46,141		(346	)
Agency collateralized mortgage obligations		8		104,071		(630	)		14		189,642		(6,699	)		22		293,713		(7,329	)
States of the U.S. and political subdivisions		1		1,427		(4	)		4		5,453		(39	)		5		6,880		(43	)
		12	$	131,586	$	(675	)		24	$	269,653	$	(7,567	)		36	$	401,239	$	(8,242	)

Summary of Cumulative Credit-Related OTTI Charges

The following table presents a summary of the cumulative credit-related OTTI charges recognized as components of earnings for securities for which a portion of an OTTI is recognized in other comprehensive income:

	Collateralized Debt Obligations			Equities		Total
For the Six Months Ended June 30, 2015
Beginning balance		—		$	27	$	27
Loss where impairment was not previously recognized		—			—		—
Additional loss where impairment was previously recognized		—			—		—
Reduction due to credit impaired securities sold		—			—		—
Ending balance		—		$	27	$	27
For the Six Months Ended June 30, 2014
Beginning balance	$	17,155		$	27	$	17,182
Loss where impairment was not previously recognized		—			—		—
Additional loss where impairment was previously recognized		—			—		—
Reduction due to credit impaired securities sold		(17,155	)		—		(17,155	)
Ending balance	$	—		$	27	$	27