Securities (Tables)

12 Months Ended

Dec. 31, 2013

Investments, Debt and Equity Securities [Abstract]

Year End Securities Held To Maturity And Available For Sale

Year-end securities held to maturity and available for sale consisted of the following:

	2013								2012
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Held to Maturity:
U.S. Treasury	$	248,592	$	20,139	$	—	$	268,731	$	248,188	$	29,859	$	—	$	278,047
Residential mortgage-backed securities	9,674		89		143		9,620		10,725		300		—		11,025
States and political subdivisions	2,880,482		7,691		137,861		2,750,312		2,696,468		15,397		4,993		2,706,872
Other	1,000		—		—		1,000		1,000		—		—		1,000
Total	$	3,139,748	$	27,919	$	138,004	$	3,029,663	$	2,956,381	$	45,556	$	4,993	$	2,996,944
Available for Sale:
U. S. Treasury	$	2,522,159	$	18,395	$	—	$	2,540,554	$	3,020,115	$	37,806	$	—	$	3,057,921
U.S. Government agencies/corporations	54,024		—		44		53,980		—		—		—		—
Residential mortgage-backed securities	1,710,664		66,791		1,439		1,776,016		2,382,514		135,514		25		2,518,003
States and political subdivisions	1,476,316		20,090		7,492		1,488,914		552,056		39,427		—		591,483
Other	35,972		—		—		35,972		35,892		—		—		35,892
Total	$	5,799,135	$	105,276	$	8,975	$	5,895,436	$	5,990,577	$	212,747	$	25	$	6,203,299

Year End Securities with Unrealized Losses, Segregated by Length of Impairment

Year-end securities with unrealized losses, segregated by length of impairment, were as follows:

	Less than 12 Months				More than 12 Months				Total
	Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses		Estimated Fair Value		Unrealized Losses
2013
Held to Maturity:
Residential mortgage-backed securities	$	6,934	$	143	$	—	$	—	$	6,934	$	143
States and political subdivisions	2,071,521		113,512		266,566		24,349		2,338,087		137,861
Total	$	2,078,455	$	113,655	$	266,566	$	24,349	$	2,345,021	$	138,004
Available for Sale:
U.S. government agencies/ corporations	$	53,980	$	44	$	—	$	—	$	53,980	$	44
Residential mortgage-backed securities	33,001		1,157		2,713		282		35,714		1,439
States and political subdivisions	679,923		7,492		—		—		679,923		7,492
Total	$	766,904	$	8,693	$	2,713	$	282	$	769,617	$	8,975
2012
Held to Maturity:
States and political subdivisions	$	353,626	$	4,993	$	—	$	—	$	353,626	$	4,993
Available for Sale:
Residential mortgage-backed securities	$	3,007	$	24	$	59	$	1	$	3,066	$	25

Amortized Cost and Estimated Fair Value of Securities, Excluding Trading Securities, Presented by Contractual Maturity

The amortized cost and estimated fair value of securities, excluding trading securities, at December 31, 2013 are presented below by contractual maturity. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations. Residential mortgage-backed securities and equity securities are shown separately since they are not due at a single maturity date.

	Held to Maturity				Available for Sale
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Due in one year or less	$	117,581	$	119,833	$	1,529,324	$	1,531,389
Due after one year through five years	493,142		526,769		1,114,932		1,133,225
Due after five years through ten years	145,483		140,891		964,001		964,144
Due after ten years	2,373,868		2,232,550		444,242		454,690
Residential mortgage-backed securities	9,674		9,620		1,710,664		1,776,016
Equity securities	—		—		35,972		35,972
Total	$	3,139,748	$	3,029,663	$	5,799,135	$	5,895,436

Sales of Securities Available for Sale

Sales of securities available for sale were as follows:

	2013			2012			2011
Proceeds from sales	$	10,056,060		$	16,587,482		$	5,587,391
Gross realized gains	1,206			6,943			6,418
Gross realized losses	(30		)	(2,629		)	(4		)
Tax (expense) benefit of securities gains/losses	(412		)	(1,510		)	(2,245		)

Year End Trading Account Securities, at Estimated Fair Value

Year-end trading account securities, at estimated fair value, were as follows:

	2013		2012
U.S. Treasury	$	15,389	$	14,038
States and political subdivisions	1,009		16,036
Total	$	16,398	$	30,074

Net Gains and Losses on Trading Account Securities

Net gains and losses on trading account securities were as follows:

	2013			2012			2011
Net gain on sales transactions	$	878		$	1,219		$	1,607
Net mark-to-market gains (losses)	(429		)	(161		)	(15		)
Net gain on trading account securities	$	449		$	1,058		$	1,592