Investment Securities (Tables)

12 Months Ended

Dec. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Available For Sale And Held For Maturity Securities [Table Text Block]

The amortized cost, gross unrealized gains and losses and estimated fair values for available-for-sale and held-to-maturity securities by major security type at December 31, 2016 and December 31, 2015 were as follows (in thousands):



December 31, 2016	Amortized Cost		Gross Unrealized Gains		Gross Unrealized (Losses)			Fair Value
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations & agencies	$	138,819	$	13	$	(2,508	)	$	136,324
Obligations of states and political subdivisions	164,163		1,346		(2,804		)	162,705
Mortgage-backed securities: GSE residential	318,829		531		(4,369		)	314,991
Trust preferred securities	3,050		—		(1,398		)	1,652
Other securities	4,034		147		(5		)	4,176
Total available-for-sale	$	628,895	$	2,037	$	(11,084	)	$	619,848
Held-to-maturity:
U.S. Treasury securities and obligations of U.S. government corporations & agencies	$	74,231	$	203	$	(1,338	)	$	73,096
December 31, 2015
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations & agencies	$	90,368	$	41	$	(268	)	$	90,141
Obligations of states and political subdivisions	107,164		3,608		(55		)	110,717
Mortgage-backed securities: GSE residential	312,132		1,374		(1,452		)	312,054
Trust preferred securities	3,130		—		(1,224		)	1,906
Other securities	4,035		29		(34		)	4,030
Total available-for-sale	$	516,829	$	5,052	$	(3,033	)	$	518,848
Held-to-maturity:
U.S. Treasury securities and obligations of U.S. government corporations & agencies	$	85,208	$	743	$	(214	)	$	85,737

During the third quarter of 2014, management evaluated its available-for-sale portfolio and transferred obligations of U.S. government corporations & agencies securities with a fair value of $53.6 million from available-for-sale to held-to-maturity to reduce price volatility. Management determined it had both the intent and ability to hold these securities to maturity. Transfers of investment securities into the held-to-maturity category from available-for-sale are made at fair value on the date of transfer. There were no gains or losses recognized as a result of this transfer. The related $1.4 million of unrealized holding loss that was included in the transfer is retained in the carrying value of the held-to-maturity securities and in other comprehensive income net of deferred taxes. These amounts are being amortized into net interest income over the remaining life of the related securities as a yield adjustment, resulting in no impact on future net income.

Trust preferred securities at December 31, 2016, is one trust preferred pooled security issued by First Tennessee Financial (“FTN”). The unrealized loss of this security, which has a maturity of twenty-one years, is primarily due to its long-term nature, a lack of demand or inactive market for the security, and concerns regarding the underlying financial institutions that have issued the trust preferred security. See the heading “Trust Preferred Securities” below for further information regarding this security.

Realized Gains and Losses From Sale of Securities

Proceeds from sales of investment securities, realized gains and losses and income tax expense and benefit were as follows during the years ended December 31, 2016, 2015 and 2014 (in thousands):



	2016		2015		2014
Proceeds from sales	$	70,757	$	19,380	$	75,618
Gross gains	1,192		452		1,452
Gross losses	—		—		737
Income tax expense	465		176		279

Investments Classified by Contractual Maturity Date

The following table indicates the expected maturities of investment securities classified as available-for-sale presented at fair value, and held-to-maturity presented at amortized cost at December 31, 2016 and the weighted average yield for each range of maturities (in thousands):



	One year or less			After 1 through 5 years			After 5 through 10 years			After ten years			Total
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	67,138		$	42,647		$	26,539		$	—		$	136,324
Obligations of state and political subdivisions	14,860			83,676			63,382			787			162,705
Mortgage-backed securities: GSE residential	572			125,297			189,122			—			314,991
Trust preferred securities	—			—			—			1,652			1,652
Other securities	—			1,995			2,037			144			4,176
Total investments	$	82,570		$	253,615		$	281,080		$	2,583		$	619,848
Weighted average yield	2.12		%	2.36		%	2.63		%	2.20		%	2.45		%
Full tax-equivalent yield	2.49		%	2.93		%	3.07		%	2.71		%	2.93		%
Held-to-maturity:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	44,992		$	29,239		$	—		$	—		$	74,231
Weighted average yield	1.79		%	2.08		%	—		%	—		%	1.90		%
Full tax-equivalent yield	1.79		%	2.08		%	—		%	—		%	1.90		%

The weighted average yields are calculated on the basis of the amortized cost and effective yields weighted for the scheduled maturity of each security. Tax-equivalent yields have been calculated using a 35% tax rate. With the exception of obligations of the U.S. Treasury and other U.S. government agencies and corporations, there were no investment securities of any single issuer, the book value of which exceeded 10% of stockholders' equity at December 31, 2016.

Fair value of investments with sustained gross unrealized losses

The following table presents the aging of gross unrealized losses and fair value by investment category as of December 31, 2016 and 2015 (in thousands):



	Less than 12 months					12 months or more					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
December 31, 2016
Available-for-sale:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	125,257	$	(2,508	)	$	—	$	—		$	125,257	$	(2,508	)
Obligations of states and political subdivisions	93,405		(2,804		)	—		—			93,405		(2,804		)
Mortgage-backed securities: GSE residential	266,319		(4,099		)	5,878		(270		)	272,197		(4,369		)
Trust preferred securities	—		—			1,652		(1,398		)	1,652		(1,398		)
Other securities	—		—			1,995		(5		)	1,995		(5		)
Total	$	484,981	$	(9,411	)	$	9,525	$	(1,673	)	$	494,506	$	(11,084	)
Held-to-maturity:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	53,295	$	(1,338	)	$	—	$	—		$	53,295	$	(1,338	)
December 31, 2015
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	34,942	$	(142	)	$	12,971	$	(126	)	$	47,913	$	(268	)
Obligations of states and political subdivisions	3,168		(32		)	979		(23		)	4,147		(55		)
Mortgage-backed securities: GSE residential	164,249		(841		)	20,011		(611		)	184,260		(1,452		)
Trust preferred securities	—		—			1,906		(1,224		)	1,906		(1,224		)
Other securities	1,966		(34		)	—		—			1,966		(34		)
Total	$	204,325	$	(1,049	)	$	35,867	$	(1,984	)	$	240,192	$	(3,033	)
Held-to-maturity:
U.S. Treasury securities and obligations of U.S. government corporations and agencies	$	35,845	$	(214	)	$	—	$	—		$	35,845	$	(214	)

Trust Preferred Securities [Table Text Block]

Following are the details for the impaired trust preferred security remaining as of December 31, 2016 (in thousands):



	Book Value		Market Value		Unrealized Gains (Losses)			Other-than- temporary Impairment Recorded To-date
PreTSL XXVIII	$	3,050	$	1,652	$	(1,398	)	$	(1,111	)

Credit Losses Recognized on Investments

As described above, some of the Company’s investments in trust preferred securities have experienced fair value deterioration due to credit losses but are not otherwise other-than-temporarily impaired. The following table provides information about those trust preferred securities for which only a credit loss was recognized in income and other losses are recorded in other comprehensive income (loss) for the years ended December 31, 2016, 2015 and 2014 (in thousands).



	Accumulated Credit Losses as of December 31:
	2016		2015		2014
Credit losses on trust preferred securities held:
Beginning of period	$	1,111	$	1,111	$	1,111
Additions related to OTTI losses not previously recognized	—		—		—
Reductions due to sales / (recoveries)	—		—		—
Reductions due to change in intent or likelihood of sale	—		—		—
Additions related to increases in previously recognized OTTI losses	—		—		—
Reductions due to increases in expected cash flows	—		—		—
End of period	$	1,111	$	1,111	$	1,111

Maturities of Investment Securities



	Amortized Cost		Estimated Fair Value
Available-for-sale:
Due in one year or less	$	83,588	$	81,998
Due after one-five years	128,818		128,318
Due after five-ten years	93,754		91,958
Due after ten years	3,906		2,583
	310,066		304,857
Mortgage-backed securities: GSE residential	318,829		314,991
Total available-for-sale	628,895		619,848
Held-to-maturity:
Due in one year or less	44,992		43,798
Due after one-five years	29,239		29,298
Due after five-ten years	—		—
Due after ten years	—		—
Total held-to-maturity	74,231		$	73,096

Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.