Available-For-Sale Securities

3 Months Ended

Mar. 31, 2012

Available-For-Sale Securities [Abstract]

Available-For-Sale Securities

(5)Available-for-sale Securities

The following tables are a summary of the available-for-sale securities portfolio as of the dates shown:

	March 31, 2012
(Dollars in thousands)	Amortized Cost		Gross unrealized gains		Gross unrealized losses			Fair Value
U.S. Treasury	$	23,063	$	128	$	(2	)	$	23,189
U.S. Government agencies		682,847		4,082		(4,149	)		682,780
Municipal		67,970		1,963		(18	)		69,915
Corporate notes and other:
Financial issuers		148,492		2,569		(9,044	)		142,017
Other		26,475		329		(5	)		26,799
Mortgage-backed: (1)
Agency		846,380		11,866		(806	)		857,440
Non-agency CMOs		28,423		286		(1	)		28,708
Other equity securities		42,664		111		(4,279	)		38,496
Total available-for-sale securities	$	1,866,314	$	21,334	$	(18,304	)	$	1,869,344
	December 31, 2011
(Dollars in thousands)	Amortized Cost		Gross unrealized gains		Gross unrealized losses			Fair Value
U.S. Treasury	$	16,028	$	145	$	—		$	16,173
U.S. Government agencies		760,533		5,596		(213	)		765,916
Municipal		57,962		2,159		(23	)		60,098
Corporate notes and other:
Financial issuers		149,229		1,914		(8,499	)		142,644
Other		27,070		287		(65	)		27,292
Mortgage-backed: (1)
Agency		206,549		12,078		(15	)		218,612
Non-agency CMOs		29,767		175		(3	)		29,939
Other equity securities		37,595		48		(6,520	)		31,123
Total available-for-sale securities	$	1,284,733	$	22,402	$	(15,338	)	$	1,291,797

(1) Consisting entirely of residential mortgage-backed securities, none of which are subprime.

The following table presents the portion of the Company's available-for-sale securities portfolio which has gross unrealized losses, reflecting the length of time that individual securities have been in a continuous unrealized loss position at March 31, 2012:

	Continuous unrealized losses existing for less than 12 months					Continuous unrealized losses existing for greater than 12 months					Total
(Dollars in thousands)	Fair value		Unrealized losses			Fair value		Unrealized losses			Fair value		Unrealized losses
U.S. Treasury	$	1,998	$	(2	)	$	—	$	—		$	1,998	$	(2	)
U.S. Government agencies		349,222		(4,149	)		—		—			349,222		(4,149	)
Municipal		6,249		(18	)		—		—			6,249		(18	)
Corporate notes and other:
Financial issuers		48,590		(4,654	)		51,556		(4,390	)		100,146		(9,044	)
Other		1,085		(5	)		—		—			1,085		(5	)
Mortgage-backed:
Agency		657,358		(806	)		—		—			657,358		(806	)
Non-agency CMOs		907		(1	)		—		—			907		(1	)
Other equity securities		26,121		(4,279	)		—		—			26,121		(4,279	)
Total	$	1,091,530	$	(13,914	)	$	51,556	$	(4,390	)	$	1,143,086	$	(18,304	)

The Company conducts a regular assessment of its investment securities to determine whether securities are other-than-temporarily impaired considering, among other factors, the nature of the securities, credit ratings or financial condition of the issuer, the extent and duration of the unrealized loss, expected cash flows, market conditions and the Company's ability to hold the securities through the anticipated recovery period.

The Company does not consider securities with unrealized losses at March 31, 2012 to be other-than-temporarily impaired. The Company does not intend to sell these investments and it is more likely than not that the Company will not be required to sell these investments before recovery of the amortized cost bases, which may be the maturity dates of the securities. The unrealized losses within each category have occurred as a result of changes in interest rates, market spreads and market conditions subsequent to purchase. Securities with continuous unrealized losses existing for more than twelve months were primarily corporate securities of financial issuers. The corporate securities of financial issuers in this category were comprised of four fixed-to-floating rate bonds and three trust-preferred securities, all of which continue to be considered investment grade. Additionally, a review of the issuers indicated that they each have strong capital ratios.

The following table provides information as to the amount of gross gains and gross losses realized and proceeds received through the sales of available-for-sale investment securities:

	Three Months Ended March 31,
(Dollars in thousands)	2012			2011
Realized gains	$	828		$	106
Realized losses		(12	)		—
Net realized gains	$	816		$	106
Other than temporary impairment charges		—			—
Gains on available- for-sale securities, net	$	816		$	106
Proceeds from sales of available-for-sale securities	$	737,369		$	50,142

The amortized cost and fair value of securities as of March 31, 2012 and December 31, 2011, by contractual maturity, are shown in the following table. Contractual maturities may differ from actual maturities as borrowers may have the right to call or repay obligations with or without call or prepayment penalties. Mortgage-backed securities are not included in the maturity categories in the following maturity summary as actual maturities may differ from contractual maturities because the underlying mortgages may be called or prepaid without penalties:

	March 31, 2012				December 31, 2011
(Dollars in thousands)	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in one year or less	$	79,980	$	80,351	$	121,400	$	121,662
Due in one to five years		496,724		494,391		532,828		530,632
Due in five to ten years		106,545		105,856		95,279		95,508
Due after ten years		265,598		264,102		261,315		264,321
Mortgage-backed		874,803		886,148		236,316		248,551
Other equity securities		42,664		38,496		37,595		31,123
Total available-for-sale securities	$	1,866,314	$	1,869,344	$	1,284,733	$	1,291,797

At March 31, 2012 and December 31, 2011, securities having a carrying value of $1.1 billion, which include securities traded but not yet settled, were pledged as collateral for public deposits, trust deposits, FHLB advances, securities sold under repurchase agreements and derivatives. At March 31, 2012, there were no securities of a single issuer, other than U.S. Government-sponsored agency securities, which exceeded 10% of shareholders' equity.