Securities (Tables)

3 Months Ended

Mar. 31, 2016

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
March 31, 2016
U.S. Treasury	$	29,771	$	223	$	—		$	29,994
U.S. government-sponsored entities		398,497		2,617		(36	)		401,078
Residential mortgage-backed securities:
Agency mortgage-backed securities		1,075,195		12,691		(21	)		1,087,865
Agency collateralized mortgage obligations		524,722		3,812		(2,904	)		525,630
Non-agency collateralized mortgage obligations		1,111		—		(15	)		1,096
Commercial mortgage-backed securities		3,674		—		(1	)		3,673
States of the U.S. and political subdivisions		39,620		283		(99	)		39,804
Other debt securities		9,754		177		(1,023	)		8,908
Total debt securities		2,082,344		19,803		(4,099	)		2,098,048
Equity securities		975		320		—			1,295
	$	2,083,319	$	20,123	$	(4,099	)	$	2,099,343
December 31, 2015
U.S. Treasury	$	29,738	$	58	$	—		$	29,796
U.S. government-sponsored entities		368,463		856		(1,325	)		367,994
Residential mortgage-backed securities:
Agency mortgage-backed securities		703,069		4,594		(2,832	)		704,831
Agency collateralized mortgage obligations		503,328		1,032		(8,530	)		495,830
Non-agency collateralized mortgage obligations		1,177		13		—			1,190
Commercial mortgage-backed securities		4,299		—		(12	)		4,287
States of the U.S. and political subdivisions		10,748		309		—			11,057
Other debt securities		14,729		208		(651	)		14,286
Total debt securities		1,635,551		7,070		(13,350	)		1,629,271
Equity securities		975		324		(3	)		1,296
	$	1,636,526	$	7,394	$	(13,353	)	$	1,630,567

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

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Securities Available for Sale
March 31, 2016
U.S. Treasury	$	29,771	$	223	$	—		$	29,994
U.S. government-sponsored entities		398,497		2,617		(36	)		401,078
Residential mortgage-backed securities:
Agency mortgage-backed securities		1,075,195		12,691		(21	)		1,087,865
Agency collateralized mortgage obligations		524,722		3,812		(2,904	)		525,630
Non-agency collateralized mortgage obligations		1,111		—		(15	)		1,096
Commercial mortgage-backed securities		3,674		—		(1	)		3,673
States of the U.S. and political subdivisions		39,620		283		(99	)		39,804
Other debt securities		9,754		177		(1,023	)		8,908
Total debt securities		2,082,344		19,803		(4,099	)		2,098,048
Equity securities		975		320		—			1,295
	$	2,083,319	$	20,123	$	(4,099	)	$	2,099,343
December 31, 2015
U.S. Treasury	$	29,738	$	58	$	—		$	29,796
U.S. government-sponsored entities		368,463		856		(1,325	)		367,994
Residential mortgage-backed securities:
Agency mortgage-backed securities		703,069		4,594		(2,832	)		704,831
Agency collateralized mortgage obligations		503,328		1,032		(8,530	)		495,830
Non-agency collateralized mortgage obligations		1,177		13		—			1,190
Commercial mortgage-backed securities		4,299		—		(12	)		4,287
States of the U.S. and political subdivisions		10,748		309		—			11,057
Other debt securities		14,729		208		(651	)		14,286
Total debt securities		1,635,551		7,070		(13,350	)		1,629,271
Equity securities		975		324		(3	)		1,296
	$	1,636,526	$	7,394	$	(13,353	)	$	1,630,567
Securities Held to Maturity
March 31, 2016
U.S. Treasury	$	500	$	184	$	—		$	684
U.S. government-sponsored entities		122,333		1,606		—			123,939
Residential mortgage-backed securities:
Agency mortgage-backed securities		830,640		18,063		(4	)		848,699
Agency collateralized mortgage obligations		520,576		4,123		(2,931	)		521,768
Non-agency collateralized mortgage obligations		2,436		4		(9	)		2,431
Commercial mortgage-backed securities		50,526		1,222		(92	)		51,656
States of the U.S. and political subdivisions		249,009		5,441		(174	)		254,276
	$	1,776,020	$	30,643	$	(3,210	)	$	1,803,453
December 31, 2015
U.S. Treasury	$	500	$	153	$	—		$	653
U.S. government-sponsored entities		137,385		809		(395	)		137,799
Residential mortgage-backed securities:
Agency mortgage-backed securities		709,970		9,858		(1,176	)		718,652
Agency collateralized mortgage obligations		499,694		803		(7,657	)		492,840
Non-agency collateralized mortgage obligations		2,681		14		—			2,695
Commercial mortgage-backed securities		51,258		115		(259	)		51,114
States of the U.S. and political subdivisions		235,573		4,191		(101	)		239,663
	$	1,637,061	$	15,943	$	(9,588	)	$	1,643,416

Gross Gains and Gross Losses Realized on Sales of Securities

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

	Three Months Ended
	March 31,
	2016		2015
Gross gains	$	71	$	—
Gross losses		—		(9	)
	$	71	$	(9	)

Amortized Cost and Fair Value of Securities, by Contractual Maturities

As of March 31, 2016, 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	$	179	$	180	$	12,126	$	12,140
Due from one to five years		441,067		444,025		114,319		115,578
Due from five to ten years		29,112		29,332		53,587		54,986
Due after ten years		7,284		6,247		191,810		196,195
		477,642		479,784		371,842		378,899
Residential mortgage-backed securities:
Agency mortgage-backed securities		1,075,195		1,087,865		830,640		848,699
Agency collateralized mortgage obligations		524,722		525,630		520,576		521,768
Non-agency collateralized mortgage obligations		1,111		1,096		2,436		2,431
Commercial mortgage-backed securities		3,674		3,673		50,526		51,656
Equity securities		975		1,295		—		—
	$	2,083,319	$	2,099,343	$	1,776,020	$	1,803,453

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
March 31, 2016
U.S. government-sponsored entities		2	$	17,960	$	(36	)		—	$	—	$	—			2	$	17,960	$	(36	)
Residential mortgage-backed securities:
Agency mortgage-backed securities		2		56,402		(21	)		—		—		—			2		56,402		(21	)
Agency collateralized mortgage obligations		2		29,786		(28	)		15		175,354		(2,876	)		17		205,140		(2,904	)
Non-agency collateralized mortgage obligations		1		1,091		(15	)		—		—		—			1		1,091		(15	)
Commercial mortgage-backed securities		1		3,673		(1	)		—		—		—			1		3,673		(1	)
States of the U.S. and political subdivisions		16		21,325		(99	)		—		—		—			16		21,325		(99	)
Other debt securities		—		—		—			3		3,875		(1,023	)		3		3,875		(1,023	)
		24	$	130,237	$	(200	)		18	$	179,229	$	(3,899	)		42	$	309,466	$	(4,099	)
December 31, 2015
U.S. government-sponsored entities		6	$	99,131	$	(814	)		2	$	34,487	$	(511	)		8	$	133,618	$	(1,325	)
Residential mortgage-backed securities:
Agency mortgage-backed securities		19		359,250		(2,832	)		—		—		—			19		359,250		(2,832	)
Agency collateralized mortgage obligations		9		126,309		(1,366	)		18		215,330		(7,164	)		27		341,639		(8,530	)
Commercial mortgage-backed securities		1		4,287		(12	)		—		—		—			1		4,287		(12	)
Other debt securities		—		—		—			3		4,245		(651	)		3		4,245		(651	)
Equity securities		1		632		(3	)		—		—		—			1		632		(3	)
		36	$	589,609	$	(5,027	)		23	$	254,062	$	(8,326	)		59	$	843,671	$	(13,353	)
Securities Held to Maturity
March 31, 2016
Residential mortgage-backed securities:
Agency mortgage-backed securities		1	$	922		(4	)		—	$	—		—			1	$	922	$	(4	)
Agency collateralized mortgage obligations		—		—		—			16		181,913		(2,931	)		16		181,913		(2,931	)
Non-agency collateralized mortgage obligations		2		1,294		(9	)		—		—		—			2		1,294		(9	)
Commercial mortgage-backed securities		1		8,579		(92	)		—		—		—			1		8,579		(92	)
States of the U.S. and political subdivisions		5		10,007		(173	)		1		2,055		(1	)		6		12,062		(174	)
		9	$	20,802	$	(278	)		17	$	183,968	$	(2,932	)		26	$	204,770	$	(3,210	)
December 31, 2015
U.S. government-sponsored entities		3	$	39,843	$	(173	)		1	$	14,778	$	(222	)		4	$	54,621	$	(395	)
Residential mortgage-backed securities:
Agency mortgage-backed securities		17		212,024		(1,159	)		1		917		(17	)		18		212,941		(1,176	)
Agency collateralized mortgage obligations		11		150,593		(1,434	)		14		160,716		(6,223	)		25		311,309		(7,657	)
Commercial mortgage-backed securities		3		46,278		(259	)		—		—		—			3		46,278		(259	)
States of the U.S. and political subdivisions		9		17,616		(101	)		—		—		—			9		17,616		(101	)
		43	$	466,354	$	(3,126	)		16	$	176,411	$	(6,462	)		59	$	642,765	$	(9,588	)

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:

	Equities		Total
For the Three Months Ended March 31, 2016
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 Three Months Ended March 31, 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