Securities (Tables)

12 Months Ended

Dec. 31, 2017

Investments Debt And Equity Securities [Abstract]

Summary of Amortized Cost and Fair Values of Securities Available-for-sale and Held to Maturity

The following tables summarize the amortized cost and fair values of securities available-for-sale and securities held-to-maturity at December 31, 2017 and 2016 and the corresponding amounts of gross unrealized gains and losses:

2017	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Available-for-sale
U.S. Treasury Notes	$	14,999	$	—	$	(136	)	$	14,863
U.S. Government agencies		54,248		—		(1,290	)		52,958
Obligations of states, municipalities, and political subdivisions		33,405		100		(335	)		33,170
Residential mortgage-backed securities
Agency		315,103		—		(7,646	)		307,457
Non-agency		39,485		104		(75	)		39,514
Commercial mortgage-backed securities
Agency		70,964		45		(1,966	)		69,043
Non-agency		31,763		—		(792	)		30,971
Corporate securities		29,573		507		(104	)		29,976
Other securities		3,627		1,730		(73	)		5,284
Total	$	593,167	$	2,486	$	(12,417	)	$	583,236

Note 4—Securities (continued)

2017	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Held-to-maturity
Obligations of states, municipalities, and political subdivisions	$	24,030	$	197	$	(82	)	$	24,145
Residential mortgage-backed securities
Agency		53,731		79		(203	)		53,607
Non-agency		39,402		174		(51	)		39,525
Total	$	117,163	$	450	$	(336	)	$	117,277

2016	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Available-for-sale
U.S. Treasury Notes	$	14,995	$	4	$	(79	)	$	14,920
U.S. Government agencies		60,180		—		(1,323	)		58,857
Obligations of states, municipalities, and political subdivisions		16,271		60		(272	)		16,059
Residential mortgage-backed securities
Agency		376,800		—		(8,640	)		368,160
Non-agency		20,107		—		(174	)		19,933
Commercial mortgage-backed securities
Agency		78,954		—		(1,551	)		77,403
Non-agency		32,061		—		(1,009	)		31,052
Corporate securities		17,065		350		(86	)		17,329
Other securities		4,161		742		(56	)		4,847
Total	$	620,594	$	1,156	$	(13,190	)	$	608,560

2016	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Held-to-maturity
Obligations of states, municipalities, and political subdivisions	$	24,878	$	105	$	(229	)	$	24,754
Residential mortgage-backed securities
Agency		67,692		35		(283	)		67,444
Non-agency		46,276		50		(442	)		45,884
Total	$	138,846	$	190	$	(954	)	$	138,082

Summary of Gross Unrealized Losses and Fair Values, Aggregated by Investment Category and Length of Individual Securities Continuous Unrealized Loss Position Available-for-sale and Held to Maturity

Gross unrealized losses and fair values, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position as of December 31, 2017 and 2016 are summarized as follows:

			Less than 12 Months					12 Months or Longer					Total
2017	# of Securities		Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Available-for-sale
U.S. Treasury Notes		5	$	4,998	$	(2	)	$	9,865	$	(134	)	$	14,863	$	(136	)
U.S. Government agencies		9		992		(7	)		51,966		(1,283	)		52,958		(1,290	)
Obligations of states, municipalities and political subdivisions		29		16,059		(137	)		4,453		(198	)		20,512		(335	)
Residential mortgage-backed securities
Agency		41		15,441		(181	)		292,016		(7,465	)		307,457		(7,646	)
Non-agency		1		—		—			4,565		(75	)		4,565		(75	)
Commercial mortgage-backed securities
Agency		7		—		—			57,442		(1,966	)		57,442		(1,966	)
Non-agency		5		—		—			30,971		(792	)		30,971		(792	)
Corporate securities		3		2,406		(80	)		2,489		(24	)		4,895		(104	)
Other securities		1		—		—			1,921		(73	)		1,921		(73	)
Total		101	$	39,896	$	(407	)	$	455,688	$	(12,010	)	$	495,584	$	(12,417	)

			Less than 12 Months					12 Months or Longer					Total
2017	# of Securities		Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Held-to-maturity
Obligations of states, municipalities, and political subdivisions		12	$	7,409	$	(38	)	$	1,548	$	(44	)	$	8,957	$	(82	)
Residential mortgage-backed securities
Agency		13		24,344		(107	)		7,935		(96	)		32,279		(203	)
Non-agency		3		10,458		(10	)		4,382		(41	)		14,840		(51	)
Total		28	$	42,211	$	(155	)	$	13,865	$	(181	)	$	56,076	$	(336	)

Note 4—Securities (continued)

			Less than 12 Months					12 Months or Longer					Total
2016	# of Securities		Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Available-for-sale
U.S. Treasury Notes		3	$	9,918	$	(79	)	$	—	$	—		$	9,918	$	(79	)
U.S. Government agencies		10		58,857		(1,323	)		—		—			58,857		(1,323	)
Obligations of states, municipalities and political subdivisions		14		7,799		(259	)		115		(13	)		7,914		(272	)
Residential mortgage-backed securities
Agency		41		364,713		(8,483	)		3,447		(157	)		368,160		(8,640	)
Non-agency		2		19,933		(174	)		—		—			19,933		(174	)
Commercial mortgage-backed securities
Agency		8		70,762		(1,488	)		6,641		(63	)		77,403		(1,551	)
Non-agency		5		31,052		(1,009	)		—		—			31,052		(1,009	)
Corporate securities		4		5,097		(78	)		2,522		(8	)		7,619		(86	)
Other securities		1		—		—			1,994		(56	)		1,994		(56	)
Total		88	$	568,131	$	(12,893	)	$	14,719	$	(297	)	$	582,850	$	(13,190	)

			Less than 12 Months					12 Months or Longer				Total
2016	# of Securities		Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Held-to-maturity
Obligations of states, municipalities, and political subdivisions		22	$	16,235	$	(229	)	$	—	$	—	$	16,235	$	(229	)
Residential mortgage-backed securities
Agency		15		52,156		(283	)		—		—		52,156		(283	)
Non-agency		5		29,245		(442	)		—		—		29,245		(442	)
Total		42	$	97,636	$	(954	)	$	—	$	—	$	97,636	$	(954	)

Summary of Proceeds From Sales of Securities Available-for-sale and Associated Gains and Losses

The proceeds from all sales of securities were available-for-sale, and the associated gains and losses for the years ended December 31, 2017, 2016, and 2015 are listed below:

	2017		2016		2015
Proceeds	$	8	$	534,418	$	511,028
Gross gains		8		3,358		3,124
Gross losses		—		131		60

Schedule of Amortized Cost and Fair Value of Debt Securities by Contractual Maturity

At December 31, 2017, the amortized cost and fair value of debt securities are shown by contractual maturity. Expected maturities may differ from contractual maturities if borrowers have the right to call or prepay obligations with or without call or prepayment penalties. Securities not due at a single maturity date are shown separately.

	Amortized Cost		Fair Value
Available-for-sale
Due in one year or less	$	8,285	$	8,268
Due from one to five years		72,432		71,826
Due from five to ten years		40,439		39,812
Due after ten years		11,604		11,738
Mortgage-backed securities		457,315		446,985
Other securities with no defined maturity		3,092		4,607
Total	$	593,167	$	583,236
Held-to-maturity
Due from one to five years	$	1,719	$	1,732
Due from five to ten years		13,532		13,546
Due after ten years		8,779		8,867
Mortgage-backed securities		93,133		93,132
Total	$	117,163	$	117,277