Note 6 - Investment Securities

The Company classifies debt and equity securities into one of three categories: held-to maturity, available-for-sale, or trading. Such securities are reassessed for appropriate classification at each reporting date. Securities classified as “held-to-maturity” are carried at amortized cost for financial statement reporting, while securities classified as “available-for-sale” and “trading” are carried at their fair value. Unrealized holding gains and losses are included in net income for those securities classified as “trading”, while unrealized holding gains and losses related to those securities classified as “available-for-sale” are excluded from net income and reported net of tax as other comprehensive income (loss) and accumulated other comprehensive income (loss) until realized, or in the case of losses, when deemed other than temporary.

The amortized cost and estimated fair value by type of investment security at September 30, 2015 are as follows:

	Held to Maturity
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Carrying Value
	(Dollars in Thousands)
Other securities	$	2,400	$	—	$	—	$	2,400	$	2,400

Total investment securities	$	2,400	$	—	$	—	$	2,400	$	2,400

	Available for Sale
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value		Carrying Value(1)
	(Dollars in Thousands)
Residential mortgage-backed securities	$	4,170,907	$	48,841	$	(22,074	)	$	4,197,674	$	4,197,674
Obligations of states and political subdivisions	293,279		18,811		(6,085		)	306,005		306,005
Equity securities	28,075		1,181		(152		)	29,104		29,104

Total investment securities	$	4,492,261	$	68,833	$	(28,311	)	$	4,532,783	$	4,532,783

(1)

Included in the carrying value of residential mortgage-backed securities are $1,287,276 of mortgage-backed securities issued by Ginnie Mae, $2,888,638 of mortgage-backed securities issued by Fannie Mae and Freddie Mac and $21,760 issued by non-government entities

The amortized cost and estimated fair value by type of investment security at December 31, 2014 are as follows:

	Held to Maturity
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Carrying Value
	(Dollars in Thousands)
Other securities	$	2,400	$	—	$	—	$	2,400	$	2,400

Total investment securities	$	2,400	$	—	$	—	$	2,400	$	2,400

	Available for Sale
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value		Carrying Value(1)
	(Dollars in Thousands)
Residential mortgage-backed securities	$	4,597,590	$	47,960	$	(45,178	)	$	4,600,372	$	4,600,372
Obligations of states and political subdivisions	268,763		19,131		(5,618		)	282,276		282,276
Equity securities	28,075		1,425		(185		)	29,315		29,315

Total investment securities	$	4,894,428	$	68,516	$	(50,981	)	$	4,911,963	$	4,911,963

(1)

Included in the carrying value of residential mortgage-backed securities are $1,503,774 of mortgage-backed securities issued by Ginnie Mae, $3,072,535 of mortgage-backed securities issued by Fannie Mae and Freddie Mac and $24,063 issued by non-government entities

The amortized cost and estimated fair value of investment securities at September 30, 2015, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to prepay obligations with or without prepayment penalties.

	Held to Maturity				Available for Sale
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(Dollars in Thousands)
Due in one year or less	$	—	$	—	$	—	$	—
Due after one year through five years	2,400		2,400		—		—
Due after five years through ten years	—		—		757		836
Due after ten years	—		—		292,522		305,169
Residential mortgage-backed securities	—		—		4,170,907		4,197,674
Equity securities	—		—		28,075		29,104

Total investment securities	$	2,400	$	2,400	$	4,492,261	$	4,532,783

Residential mortgage-backed securities are securities issued by Freddie Mac, Fannie Mae, Ginnie Mae or non-government entities. Investments in residential mortgage-backed securities issued by Ginnie Mae are fully guaranteed by the U.S. Government. Investments in mortgage-backed securities issued by Freddie Mac and Fannie Mae are not fully guaranteed by the U.S. Government, however, the Company believes that the quality of the bonds is similar to other AAA rated bonds with limited credit risk, particularly given the placement of Fannie Mae and Freddie Mac into conservatorship by the federal government in early September 2008 and because securities issued by others that are collateralized by residential mortgage-backed securities issued by Fannie Mae or Freddie Mac are rated consistently as AAA rated securities.

The amortized cost and fair value of available for sale investment securities pledged to qualify for fiduciary powers, to secure public monies as required by law, repurchase agreements and short-term fixed borrowings was $1,858,273,000 and $1,874,111,000, respectively, at September 30, 2015.

Proceeds from the sale of securities available-for-sale were $0 and $30,282,000 for the three and nine months ended September 30, 2015, which included $0 and $23,992,000 of mortgage-backed securities, respectively. Gross gains of $0 and $0 and gross losses of $0 and $428,000 were realized on the sales for the three and nine months ended September 30, 2015, respectively. Proceeds from the sale of securities available-for-sale were $253,292,000 and $621,588,000 for the three and nine months ended September 30, 2014, which included $253,292,000 and $620,933,000 of mortgage-backed securities. Gross gains of $0 and $9,479,000 and gross losses of $6,446,000 and $8,196,000 were realized on the sales for the three and nine months ended September 30, 2014, respectively.

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 September 30, 2015, were as follows:

	Less than 12 months					12 months or more					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
	(Dollars in Thousands)
Available for sale:
Residential mortgage-backed securities	$	276,858	$	(1,190	)	$	1,485,041	$	(20,884	)	$	1,761,899	$	(22,074	)
Obligations of states and political subdivisions	9,306		(111		)	25,521		(5,974		)	34,827		(6,085		)
Equity securities	72		(4		)	5,602		(148		)	5,674		(152		)

	$	286,236	$	(1,305	)	$	1,516,164	$	(27,006	)	$	1,802,400	$	(28,311	)

	Less than 12 months					12 months or more					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
	(Dollars in Thousands)
Available for sale:
Residential mortgage-backed securities	$	808,072	$	(4,910	)	$	1,836,218	$	(40,268	)	$	2,644,290	$	(45,178	)
Obligations of states and political subdivisions	8,833		(97		)	27,793		(5,521		)	36,626		(5,618		)
Equity securities	74		(1		)	8,066		(184		)	8,140		(185		)

	$	816,979	$	(5,008	)	$	1,872,077	$	(45,973	)	$	2,689,056	$	(50,981	)

The unrealized losses on investments in residential mortgage-backed securities are primarily caused by changes in market interest rates. Residential mortgage-backed securities are primarily securities issued by Freddie Mac, Fannie Mae and Ginnie Mae. The contractual cash obligations of the securities issued by Ginnie Mae are fully guaranteed by the U.S. Government. The contractual cash obligations of the securities issued by Freddie Mac and Fannie Mae are not fully guaranteed by the U.S. Government; however, the Company believes that the quality of the bonds is similar to other AAA rated bonds with limited credit risk, particularly given the placement of Fannie Mae and Freddie Mac into conservatorship by the federal government in early September 2008 and because securities issued by others that are collateralized by residential mortgage-backed securities issued by Fannie Mae and Freddie Mac are rated consistently as AAA rated securities. The decrease in fair value on residential mortgage-backed securities issued by Freddie Mac, Fannie Mae and Ginnie Mae is due to market interest rates. The Company has no intent to sell and will more than likely not be required to sell before a market price recovery or maturity of the securities; therefore, it is the conclusion of the Company that the investments in residential mortgage-backed securities issued by Freddie Mac, Fannie Mae and Ginnie Mae are not considered other-than-temporarily impaired. In addition, the Company has a small investment in non-agency residential mortgage-backed securities that have additional market volatility beyond economically induced interest rate events and the Company has concluded that the investments in non-agency residential mortgage-backed securities are other-than-temporarily impaired due to both credit and other than credit issues. Impairment charges of $700,000 ($455,000, after tax) and $249,000 ($161,850, after tax) were recorded for the three and nine months ended September 30, 2015, respectively. Impairment charges of $273,000 ($177,000, after tax) and $552,000 ($359,000, after tax) were recorded for the three and nine months ended September 30, 2014, respectively. The impairment charge represents the credit related impairment on the securities.

The unrealized losses on investments in other securities are caused by fluctuations in market interest rates. The underlying cash obligations of the securities are guaranteed by the entity underwriting the debt instrument. It is the belief of the Company that the entity issuing the debt will honor its interest payment schedule, as well as the full debt at maturity. The securities are purchased by the Company for their economic value. The decrease in fair value is primarily due to market interest rates and not other factors, and because the Company has no intent to sell and will more than likely not be required to sell before a market price recovery or maturity of the securities, it is the conclusion of the Company that the investments are not considered other-than-temporarily impaired.

The following table presents a reconciliation of credit-related impairment charges on available-for-sale investments recognized in earnings for the three months ended September 30, 2015 (Dollars in Thousands):

Balance at June 30, 2015	$	13,074
Impairment charges recognized during period	249

Balance at September 30, 2015	$	13,323

The following table presents a reconciliation of credit-related impairment charges on available-for-sale investments recognized in earnings for the nine months ended September 30, 2015 (Dollars in Thousands):

Balance at December 31, 2014	$	12,623
Impairment charges recognized during period	700

Balance at September 30, 2015	$	13,323

The following table presents a reconciliation of credit-related impairment charges on available-for-sale investment recognized in earnings for the three months ended September 30, 2014 (Dollars in Thousands):

Balance at June 30, 2014	$	12,085
Impairment charges recognized during period	273

Balance at September 30, 2014	$	12,358

The following table presents a reconciliation of credit-related impairment charges on available-for-sale investment recognized in earnings for the nine months ended September 30, 2014 (Dollars in Thousands):

Balance at December 31, 2013	$	11,806
Impairment charges recognized during period	552

Balance at September 30, 2014	$	12,358