Securities (Tables)

3 Months Ended

Mar. 31, 2015

Investments Debt And Equity Securities [Abstract]

Summary of Securities Held for Investment and Securities Available for Sale

The following table summarizes securities held for investment and securities available for sale:

	March31, 2015
	(Dollars in thousands)
Held for investment, at cost (fair value: $8,350)	$	8,281
Available for sale, at fair value		541,844
Total	$	550,125

Summary of Amortized Cost and Estimated Fair Values of Securities Held for Investment

The following table summarizes the amortized cost and estimated fair values of securities held for investment:

	March 31, 2015
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
	(Dollars in thousands)
Mortgage backed securities (1)	$	439	$	32	$	—	$	471
States and political subdivisions		7,842		37		—		7,879
Total	$	8,281	$	69	$	—	$	8,350

Summary of Amortized Cost and Estimated Fair Values of Securities Available for Sale

The following table summarizes the amortized cost and estimated fair values of securities available for sale:

	March 31, 2015
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(Dollars in thousands)
U.S. treasuries	$	279,498	$	1,717	$	-		$	281,215
U.S. federal agencies		168,514		1,010		(62	)		169,462
Mortgage backed securities (1)		25,272		595		(567	)		25,300
States and political subdivisions		49,631		1,868		(19	)		51,480
Other securities (2)		10,887		3,633		(133	)		14,387
Total	$	533,802	$	8,823	$	(781	)	$	541,844

(1) Primarily consists of FHLMC, FNMA, GNMA and mortgage backed securities through U.S. agencies.

(2) Primarily consists of equity securities.

Maturity of Securities

The maturities of securities held for investment and available for sale are summarized in the following table using contractual maturities. Actual maturities may differ from contractual maturities due to obligations that are called or prepaid. For purposes of the maturity table, mortgage-backed securities, which are not due at a single maturity date, have been presented at their contractual maturity.

	March 31, 2015
	Amortized Cost		Estimated Fair Value
	(Dollars in thousands)
Held for Investment
Contractual maturity of debt securities:
Within one year	$	1,373	$	1,380
After one year but within five years		6,399		6,429
After five years but within ten years		368		383
After ten years		141		158
Total	$	8,281	$	8,350
Available for Sale
Contractual maturity of debt securities:
Within one year	$	91,839	$	91,928
After one year but within five years		333,138		336,018
After five years but within ten years		16,864		17,653
After ten years		84,514		85,341
Total debt securities		526,355		530,940
Equity securities		7,447		10,904
Total	$	533,802	$	541,844

Company's Book Value of Pledged Securities

The following table is a summary of the Company’s book value of securities that were pledged as collateral for public funds on deposit, repurchase agreements and for other purposes as required or permitted by law:

	March 31, 2015
	(Dollarsin thousands)
Book value of pledged securities	$	482,193