Securities

At December 31, 2015 the Company’s securities portfolio primarily consisted of securities issued by the U.S. government, U.S. government agencies, U.S. government-sponsored enterprises and state and municipalities. All of the Company’s mortgage-backed securities and collateralized mortgage obligations are issued by U.S. government agencies and U.S. government-sponsored enterprises and are implicitly guaranteed by the U.S. government. The Company had no other issuances in its portfolio which exceeded ten percent of shareholders’ equity.

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
December 31, 2015	(in thousands)
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	1,296,955	$	4,525	$	(14,991	)	$	1,286,489
State and municipal securities	480,417		12,690		(938		)	492,169
U.S. government agency and government-sponsored enterprise securities	354,515		1,113		(1,846		)	353,782
U.S. government securities	20,439		—		(302		)	20,137
Other securities	5,284		24		(191		)	5,117
Total	$	2,157,610	$	18,352	$	(18,268	)	$	2,157,694
December 31, 2014
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	1,160,378	$	10,219	$	(8,210	)	$	1,162,387
State and municipal securities	483,578		14,432		(1,526		)	496,484
U.S. government agency and government-sponsored enterprise securities	416,919		856		(4,069		)	413,706
U.S. government securities	20,910		—		(411		)	20,499
Other securities	5,284		20		(123		)	5,181
Total	$	2,087,069	$	25,527	$	(14,339	)	$	2,098,257

Proceeds from sales of securities available-for-sale were $95.4 million, $63.3 million and $166.9 million for the years ended December 31, 2015, 2014 and 2013, respectively. The following table provides the gross realized gains and losses on the sales and calls of securities for the periods indicated:



	Years Ended December 31,
	2015			2014			2013
	(in thousands)
Gross realized gains	$	1,591		$	553		$	632
Gross realized losses	(10		)	(1		)	(170		)
Net realized gains	$	1,581		$	552		$	462

The scheduled contractual maturities of investment securities available for sale at December 31, 2015 are presented as follows:



	December 31, 2015
	Amortized Cost		Fair Value
	(in thousands)
Due within one year	$	22,191	$	22,418
Due after one year through five years	458,889		458,372
Due after five years through ten years	702,234		703,088
Due after ten years	969,012		968,699
Other securities with no stated maturity	5,284		5,117
Total investment securities available-for-sale	$	2,157,610	$	2,157,694

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



	December 31, 2015		December 31, 2014
	(in thousands)
Washington and Oregon State to secure public deposits	$	341,079	$	328,400
Federal Reserve Bank to secure borrowings	48,714		41,146
Other securities pledged	143,606		157,097
Total securities pledged as collateral	$	533,399	$	526,643

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 December 31, 2015 and 2014:



	Less than 12 Months					12 Months or More					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
December 31, 2015	(in thousands)
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	664,509	$	(7,610	)	$	214,325	$	(7,381	)	$	878,834	(14,991		)
State and municipal securities	48,261		(358		)	31,383		(580		)	79,644		(938		)
U.S. government agency and government-sponsored enterprise securities	193,400		(1,128		)	40,034		(718		)	233,434		(1,846		)
U.S. government securities	10,343		(136		)	9,794		(166		)	20,137		(302		)
Other securities	2,300		(15		)	2,780		(176		)	5,080		(191		)
Total	$	918,813	$	(9,247	)	$	298,316	$	(9,021	)	$	1,217,129	$	(18,268	)
December 31, 2014
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	258,825	$	(1,287	)	$	279,015	$	(6,924	)	$	537,840	$	(8,211	)
State and municipal securities	71,026		(543		)	44,148		(982		)	115,174		(1,525		)
U.S. government agency and government-sponsored enterprise securities	105,250		(518		)	216,221		(3,551		)	321,471		(4,069		)
U.S. government securities	—		—			19,450		(411		)	19,450		(411		)
Other securities	2,313		(2		)	2,834		(121		)	5,147		(123		)
Total	$	437,414	$	(2,350	)	$	561,668	$	(11,989	)	$	999,082	$	(14,339	)

At December 31, 2015, there were 143 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations securities in an unrealized loss position, of which 49 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 currently 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 upon maturity, the Company does not consider these investments to be other-than-temporarily impaired at December 31, 2015.

At December 31, 2015, there were 67 state and municipal government securities in an unrealized loss position, of which 27 were 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 December 31, 2015 none of the rated obligations of state and local government entities held by the Company had a below investment grade credit rating. Because the credit quality of these securities are investment grade and the Company does not currently 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 upon maturity, the Company does not consider these investments to be other-than-temporarily impaired at December 31, 2015.

At December 31, 2015, there were 25 U.S. government agency and government-sponsored enterprise securities in an unrealized loss position, of which five 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 currently 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 upon maturity, the Company does not consider these investments to be other-than-temporarily impaired at December 31, 2015.

At December 31, 2015, there were three U.S. government securities in an unrealized loss position, one of which was 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 currently 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 upon maturity, the Company does not consider this investment to be other-than-temporarily impaired at December 31, 2015.

At December 31, 2015, there were two other securities in an unrealized loss position, of which one security, a mortgage-backed securities fund was 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 December 31, 2015 as it has the intent and ability to hold the investment for sufficient time to allow for recovery in the market value.