Securities

The following table summarizes the amortized cost, gross unrealized gains and losses and the resulting fair value of securities available for sale:



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
March 31, 2012
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	652,263	$	18,650	$	(1,329	)	$	669,584
State and municipal securities	263,298		20,466		(212		)	283,552
U.S. government agency and government-sponsored enterprise securities	42,439		350		(37		)	42,752
Other securities	3,296		60		(31		)	3,325
Total	$	961,296	$	39,526	$	(1,609	)	$	999,213
December 31, 2011
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	678,631	$	19,323	$	(2,000	)	$	695,954
State and municipal securities	263,075		22,746		(58		)	285,763
U.S. government agency and government-sponsored enterprise securities	42,558		505		—			43,063
Other securities	3,296		64		(30		)	3,330
Total	$	987,560	$	42,638	$	(2,088	)	$	1,028,110

The scheduled contractual maturities of investment securities available for sale at March 31, 2012 are presented as follows:



	March 31, 2012
	Amortized Cost		Fair Value
	(in thousands)
Due within one year	$	22,442	$	22,749
Due after one year through five years	78,072		80,627
Due after five years through ten years	190,442		199,359
Due after ten years	667,044		693,153
Total investment securities available-for-sale	$	958,000	$	995,888

The following table summarizes, as of March 31, 2012, the carrying value of securities pledged as collateral to secure public deposits, borrowings and other purposes as permitted or required by law:



	Carrying Amount
	(in thousands)
To Washington and Oregon State to secure public deposits	$	213,713
To Federal Home Loan Bank to secure advances	87,180
To Federal Reserve Bank to secure borrowings	54,778
Other securities pledged	47,878
Total securities pledged as collateral	$	403,549

The following tables show the gross unrealized losses and fair value of the Company’s investments with unrealized losses that are not deemed to be other-than-temporarily impaired, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at March 31, 2012 and December 31, 2011:




	Less than 12 Months					12 Months or More					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
	(in thousands)
March 31, 2012
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	166,921	$	(1,228	)	$	12,035	$	(101	)	$	178,956	(1,329		)
State and municipal securities	8,251		(188		)	960		(24		)	9,211		(212		)
U.S. government agency and government-sponsored enterprise securities	13,932		(37		)	—		—			13,932		(37		)
Other securities	—		—			969		(31		)	969		(31		)
Total	$	189,104	$	(1,453	)	$	13,964	$	(156	)	$	203,068	$	(1,609	)

December 31, 2011
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	238,875	$	(1,999	)	$	196	$	(1	)	$	239,071	$	(2,000	)
State and municipal securities	3,820		(24		)	950		(34		)	4,770		(58		)
Other securities	—		—			970		(30		)	970		(30		)
Total	$	242,695	$	(2,023	)	$	2,116	$	(65	)	$	244,811	$	(2,088	)

At March 31, 2012, there were eleven state and municipal government securities in an unrealized loss position, of which one was in a continuous loss position for 12 months or more. The unrealized losses on state and municipal securities were caused by interest rate changes or widening of market spreads subsequent to the purchase of the individual securities. Management monitors published credit ratings of these securities for adverse changes. As of March 31, 2012 none of the rated obligations of state and local government entities held by the Company had an adverse credit rating. Because the credit quality of these securities are investment grade and the Company does not intend to sell these securities nor does the Company consider it more likely than not that it will be required to sell these securities before the recovery of amortized cost basis, which may be maturity, the Company does not consider these investments to be other-than-temporarily impaired at March 31, 2012.

At March 31, 2012, there were 34 U.S. government agency and government-sponsored enterprise mortgage-backed securities & collateralized mortgage obligations securities in an unrealized loss position, of which two were in a continuous loss position for 12 months or more. The decline in fair value is attributable to changes in interest rates relative to where these investments fall within the yield curve and their individual characteristics. Because the Company does not intend to sell these securities nor does the Company consider it more likely than not that it will be required to sell these securities before the recovery of amortized cost basis, which may be maturity, the Company does not consider these investments to be other-than-temporarily impaired at March 31, 2012.

At March 31, 2012, there was one U.S. government agency and government-sponsored enterprise security in an unrealized loss position for less than 12 months. The decline in fair value is attributable to changes in interest rates relative to where this investment falls within the yield curve and its individual characteristics. Because the Company does not intend to sell this security nor does the Company consider it more likely than not that it will be required to sell this security before the recovery of amortized cost basis, which may be maturity, the Company does not consider this investment to be other-than-temporarily impaired at March 31, 2012.

At March 31, 2012, there was one other security, a mortgage-backed securities fund in a continuous unrealized loss position for 12 months or more. The decline in fair value is attributable to changes in interest rates and the additional risk premium investors are demanding for investment securities with these characteristics. The Company does not consider this investment to be other-than-temporarily impaired at March 31, 2012 as it has the intent and ability to hold the investment for sufficient time to allow for recovery in the market value.