6. Securities

The amortized cost and fair value of securities classified as available for sale follow (in thousands):


	June 30, 2011								December 31, 2010
			Gross		Gross						Gross		Gross
	Amortized		Unrealized		Unrealized		Fair		Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value		Cost		Gains		Losses		Value
U.S. Treasury	$	10,804	$	47	$	—	$	10,851	$	10,797	$	52	$	5		10,844
U.S. government agencies		424,141		2,141		802		425,480		106,054		971		434		106,591
Municipal obligations		311,316		8,055		535		318,836		181,747		4,107		5,411		180,443
Mortgage-backed securities		2,248,990		42,452		6,315		2,285,127		761,704		38,032		50		799,686
CMOs		1,503,096		8,849		2,220		1,509,725		367,662		6,880		2,491		372,051
Other debt securities		17,950		957		23		18,884		14,329		999		43		15,285
Other equity securities		4,496		672		98		5,070		3,428		660		103		3,985

	$	4,520,793	$	63,173	$	9,993	$	4,573,973	$	1,445,721	$	51,701	$	8,537	$	1,488,885

The amortized cost and fair value of securities classified as available for sale at June 30, 2011, by contractual maturity, (expected maturities will differ from contractual maturities because of rights to call or repay obligations with or without penalties (in thousands):


	Amortized		Fair
	Cost		Value

Securities Available for Sale

Due in one year or less	$	460,313	$	461,814
Due after one year through five years		914,213		917,332
Due after five years through ten years		462,327		474,997
Due after ten years		2,679,444		2,714,760
Equity securities		4,496		5,070

Total available for sale securities	$	4,520,793	$	4,573,973

The Company held no securities classified as held to maturity or trading at June 30, 2011 or December 31, 2010.

The details concerning securities classified as available for sale with unrealized losses as of June 30, 2011 follow (in thousands):


	Losses < 12 months				Losses 12 months or >				Total
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
U.S. Treasury	$	—	$	—	$	—	$	—	$	—	$	—
U.S. government agencies		117,917		802		—		—		117,917		802
Municipal obligations		75,975		210		12,515		325		88,490		535
Mortgage-backed securities		1,508,442		6,253		1,253		61		1,509,695		6,314
CMOs		518,953		2,220		—		—		518,953		2,220
Other debt securities		56		1		316		23		372		24
Equity securities		2,425		78		14		20		2,439		98

	$	2,223,768	$	9,564	$	14,098	$	429	$	2,237,866	$	9,993

The details concerning securities classified as available for sale with unrealized losses as of December 31, 2010 follow (in thousands):


	Losses < 12 months				Losses 12 months or >				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses

U.S. Treasury	$	9,980	$	5	$	—	$	—	$	9,980	$	5
U.S. government agencies		74,566		434		—		—		74,566		434
Municipal obligations		57,713		3,092		19,870		2,319		77,583		5,411
Mortgage-backed securities		122		1		1,340		49		1,462		50
CMOs		122,312		2,491		—		—		122,312		2,491
Other debt securities		379		6		459		37		838		43
Equity securities		2,552		87		11		16		2,563		103

	$	267,624	$	6,116	$	21,680	$	2,421	$	289,304	$	8,537

The unrealized losses relate to fixed-rate debt securities that have incurred fair value reductions due to higher market interest rates since the respective purchase date. The unrealized losses are not likely to reverse unless and until market interest rates decline to the levels that existed when the securities were purchased. Since none of the unrealized losses relate to the marketability of the securities or the issuer's ability to honor redemption obligations, none of the securities are deemed to be other than temporarily impaired.

As of June 30, 2011, the securities portfolio totaled $4.6 billion and as of December 31, 2010, the securities portfolio totaled $1.4 billion. Of the total portfolio, $2.2 billion of securities were in an unrealized loss position of $10 million. Management and the Asset/Liability Committee continually monitor the securities portfolio and management is able to effectively measure and monitor the unrealized loss position on these securities. The Company has adequate liquidity and therefore does not plan to sell and is more likely than not, not to be required to sell these securities before recovery. Accordingly, the unrealized loss of these securities has not been determined to be other than temporary.

Securities with a carrying value of approximately $2.7 billion at June 30, 2011 and $1.3 billion at December 31, 2010 were pledged primarily to secure public deposits and securities sold under agreements to repurchase.

Short-term Investments

The Company held no short-term investments at June 30, 2011 and $275.0 million at December 31, 2010 in U.S. government agency discount notes as securities available for sale at amortized cost. Short-term investments all mature in less than 1 year. As the amortized cost is a reasonable estimate for fair value of these short-term investments, there were no gross unrealized losses to evaluate for impairment at December 31, 2010.