Interest-Bearing Time Deposits in Banks and Securities (Tables)

12 Months Ended

Dec. 31, 2012

Summary of Available-for-Sale and Held-to-Maturity Securities

A summary of the Company’s available-for-sale and held-to-maturity securities as of December 31, 2012 and 2011 are as follows (in thousands):

	December 31, 2012
	Amortized Cost Basis		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Estimated Fair Value
Securities available-for-sale:
U. S. Treasury securities	$	6,042	$	48	$	—		$	6,090
Obligations of U.S. government sponsored-enterprises and agencies		219,420		4,060		—			223,480
Obligations of state and political subdivisions		786,278		57,541		(129	)		843,690
Corporate bonds and other		117,244		6,020		(73	)		123,191
Residential mortgage-backed securities		564,434		23,285		(443	)		587,276
Commercial mortgage-backed securities		33,819		1,739		(250	)		35,308
Total securities available-for-sale	$	1,727,237	$	92,693	$	(895	)	$	1,819,035
Securities held-to-maturity:
Obligations of state and political subdivisions	$	735	$	7	$	—		$	742
Residential mortgage-backed securities		294		11		—			305
Commercial mortgage-backed securities		32		1		—			33
Total debt securities held-to-maturity	$	1,061	$	19	$	—		$	1,080

	December 31, 2011
	Amortized Cost Basis		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Estimated Fair Value
Securities available-for-sale:
U. S. Treasury Securities	$	15,143	$	204	$	—		$	15,347
Obligations of U.S. government sponsored-enterprises and agencies		255,548		5,802		(4	)		261,346
Obligations of state and political subdivisions		655,957		48,812		(98	)		704,671
Corporate bonds and other		127,514		4,215		(255	)		131,474
Residential mortgage-backed securities		681,277		24,247		(89	)		705,435
Commercial mortgage-backed securities		22,003		1,113		—			23,116
Total securities available-for-sale	$	1,757,442	$	84,393	$	(446	)	$	1,841,389
Securities held-to-maturity:
Obligations of state and political subdivisions	$	3,187	$	30	$	—		$	3,217
Residential mortgage-backed securities		358		14		—			372
Commercial mortgage-backed securities		64		2		—			66
Total debt securities held-to-maturity	$	3,609	$	46	$	—		$	3,655

Amortized Cost and Estimated Fair Value of Debt Securities

The amortized cost and estimated fair value of debt securities at December 31, 2012, by contractual and expected maturity, are shown below (in thousands):

	Available-for-Sale				Held-to-Maturity
	Amortized Cost Basis		Estimated Fair Value		Amortized Cost Basis		Estimated Fair Value
Due within one year	$	156,237	$	158,605	$	655	$	658
Due after one year through five years		494,482		514,761		80		84
Due after five years through ten years		467,185		509,127		—		—
Due after ten years		11,080		13,958		—		—
Mortgage-backed securities		598,253		622,584		326		338
Total	$	1,727,237	$	1,819,035	$	1,061	$	1,080

Continuous Unrealized-Loss Position Of Available-For-Sale And Held-To-Maturity Securities

The following table discloses, as of December 31, 2012 and 2011, the Company’s investment securities that have been in a continuous unrealized-loss position for less than 12 months and for 12 or more months (in thousands):

	Less than 12 Months				12 Months or Longer				Total
December 31, 2012	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Obligations of state and political subdivisions	$	36,480	$	129	$	—	$	—	$	36,480	$	129
Residential mortgage-backed securities		17,344		401		3,574		42		20,918		443
Commercial mortgage-backed securities		12,453		250		—		—		12,453		250
Corporate bonds and other		4,994		73		—		—		4,994		73
Total	$	71,271	$	853	$	3,574	$	42	$	74,845	$	895

	Less than 12 Months				12 Months or Longer				Total
December 31, 2011	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Obligations of U. S. government sponsored-enterprises and agencies	$	3,114	$	4	$	—	$	—	$	3,114	$	4
Obligations of state and political subdivisions		9,595		98		—		—		9,595		98
Residential mortgage-backed securities		13,722		89		—		—		13,722		89
Corporate bonds and other		17,533		255		—		—		17,533		255
Total	$	43,964	$	446	$	—	$	—	$	43,964	$	446