Note 3 - Investment Securities

The amortized cost, gross unrealized gains and losses, and estimated fair values of investment securities available for sale at March 31, 2016 and December 31, 2015 are summarized below.



	March 31, 2016
(in thousands)	Amortized Cost		Gross Unrealized Gains	Gross Unrealized Losses		Fair Value
U.S. Treasury securities	$	43,147	559	—		43,706
U.S. Government agency securities	13,016		534	—		13,550
Securities issued by U.S. Government sponsored enterprises	126,305		297	—		126,602
Mortgage-backed securities issued by U.S. Government agencies	191,386		2,653	(143	)	193,896
Mortgage-backed securities issued by U.S. Government sponsored enterprises	2,599,118		24,787	(1,771	)	2,622,134
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises	542,761		7,687	(393	)	550,055
State and municipal securities	3,964		76	(1	)	4,039
Equity securities	3,228		4,976	—		8,204
Other investments	20,194		286	(422	)	20,058
Total investment securities available for sale	$	3,543,119	41,855	(2,730	)	3,582,244

	December 31, 2015
(in thousands)	Amortized Cost		Gross Unrealized Gains	Gross Unrealized Losses		Fair Value
U.S. Treasury securities	$	43,125	232	—		43,357
U.S. Government agency securities	13,087		536	—		13,623
Securities issued by U.S. Government sponsored enterprises	126,520		389	—		126,909
Mortgage-backed securities issued by U.S. Government agencies	209,785		1,340	(1,121	)	210,004
Mortgage-backed securities issued by U.S. Government sponsored enterprises	2,645,107		7,874	(22,562	)	2,630,419
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises	530,426		2,396	(3,225	)	529,597
State and municipal securities	4,343		92	(1	)	4,434
Equity securities	3,228		6,444	—		9,672
Other investments	20,177		—	(374	)	19,803
Total investment securities available for sale	$	3,595,798	19,303	(27,283	)	3,587,818

At March 31, 2016 and December 31, 2015, investment securities with a carrying value of $2.27 billion and $2.43 billion respectively, were pledged to secure certain deposits and securities sold under repurchase agreements as required by law and contractual agreements.

Synovus has reviewed investment securities that are in an unrealized loss position as of March 31, 2016 and December 31, 2015 for OTTI and does not consider any securities in an unrealized loss position to be other-than-temporarily impaired. If Synovus intended to sell a security in an unrealized loss position, the entire unrealized loss would be reflected in income. Synovus does not intend to sell investment securities in an unrealized loss position prior to the recovery of the unrealized loss, which may be until maturity, and has the ability and intent to hold those securities for that period of time. Additionally, Synovus is not currently aware of any circumstances which will require it to sell any of the securities that are in an unrealized loss position prior to the respective securities' recovery of all such unrealized losses.

Declines in the fair value of available for sale securities below their cost that are deemed to have OTTI are reflected in earnings as realized losses to the extent the impairment is related to credit losses. The amount of the impairment related to other factors is recognized in other comprehensive income. Currently, unrealized losses on debt securities are attributable to increases in interest rates on comparable securities from the date of purchase. Synovus regularly evaluates its investment securities portfolio to ensure that there are no conditions that would indicate that unrealized losses represent OTTI. These factors include the length of time the security has been in a loss position, the extent that the fair value is below amortized cost, and the credit standing of the issuer. As of March 31, 2016, Synovus had twenty-two investment securities in a loss position for less than twelve months and twelve investment securities in a loss position for twelve months or longer.

Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at March 31, 2016 and December 31, 2015, are presented below.



	March 31, 2016
	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
Mortgage-backed securities issued by U.S. Government agencies	—		—	11,938	143	11,938	143
Mortgage-backed securities issued by U.S. Government sponsored enterprises	559,661		1,602	29,281	169	588,942	1,771
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises	—		—	71,875	393	71,875	393
State and municipal securities	—		—	51	1	51	1
Other investments	—		—	4,771	422	4,771	422
Total	$	559,661	1,602	117,916	1,128	677,577	2,730

	December 31, 2015
	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
Mortgage-backed securities issued by U.S. Government agencies	122,626		639	18,435	482	141,061	1,121
Mortgage-backed securities issued by U.S. Government sponsored enterprises	1,656,194		12,874	489,971	9,688	2,146,165	22,562
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises	196,811		963	72,366	2,262	269,177	3,225
State and municipal securities	—		—	50	1	50	1
Other investments	14,985		15	4,818	359	19,803	374
Total	$	1,990,616	14,491	585,640	12,792	2,576,256	27,283

The amortized cost and fair value by contractual maturity of investment securities available for sale at March 31, 2016 are shown below. The expected life of mortgage-backed securities or CMOs may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. For purposes of the maturity table, mortgage-backed securities and CMOs, which are not due at a single maturity date, have been classified based on the final contractual maturity date.



	Distribution of Maturities at March 31, 2016
(in thousands)	Within One Year		1 to 5 Years	5 to 10 Years	More Than 10 Years	No Stated Maturity	Total
Amortized Cost
U.S. Treasury securities	$	18,256	24,891	—	—	—	43,147
U.S. Government agency securities	—		6,614	6,402	—	—	13,016
Securities issued by U.S. Government sponsored enterprises	80,240		46,065	—	—	—	126,305
Mortgage-backed securities issued by U.S. Government agencies	—		—	17,447	173,939	—	191,386
Mortgage-backed securities issued by U.S. Government sponsored enterprises	—		566	1,333,864	1,264,688	—	2,599,118
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises	—		—	—	542,761	—	542,761
State and municipal securities	1,037		350	—	2,577	—	3,964
Equity securities	—		—	—	—	3,228	3,228
Other investments	—		—	15,000	2,000	3,194	20,194
Total amortized cost	$	99,533	78,486	1,372,713	1,985,965	6,422	3,543,119

Fair Value
U.S. Treasury securities	$	18,256	25,450	—	—	—	43,706
U.S. Government agency securities	—		6,849	6,701	—	—	13,550
Securities issued by U.S. Government sponsored enterprises	80,398		46,204	—	—	—	126,602
Mortgage-backed securities issued by U.S. Government agencies	—		—	17,810	176,086	—	193,896
Mortgage-backed securities issued by U.S. Government sponsored enterprises	—		588	1,341,168	1,280,378	—	2,622,134
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises	—		—	—	550,055	—	550,055
State and municipal securities	1,049		352	—	2,638	—	4,039
Equity securities	—		—	—	—	8,204	8,204
Other investments	—		—	15,287	1,638	3,133	20,058
Total fair value	$	99,703	79,443	1,380,966	2,010,795	11,337	3,582,244

Proceeds from sales, gross gains, and gross losses on sales of securities available for sale for the three months ended March 31, 2016 and 2015 are presented below. The specific identification method is used to reclassify gains and losses out of other comprehensive income at the time of sale.



	Three Months Ended March 31,
(in thousands)	2016			2015
Proceeds from sales of investment securities available for sale	$	243,609		32,419
Gross realized gains	954			725
Gross realized losses	(887		)	—
Investment securities gains, net	$	67		725