Securities

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



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
June 30, 2018	(in thousands)
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	1,732,779	$	567	$	(56,354	)	$	1,676,992
State and municipal securities	584,587		2,984		(9,876		)	577,695
U.S. government agency and government-sponsored enterprise securities	398,428		74		(7,228		)	391,274
U.S. government securities	251		—		(4		)	247
Total	$	2,716,045	$	3,625	$	(73,462	)	$	2,646,208
December 31, 2017
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	1,752,236	$	1,815	$	(27,326	)	$	1,726,725
State and municipal securities	593,940		6,023		(3,959		)	596,004
U.S. government agency and government-sponsored enterprise securities	416,894		642		(2,762		)	414,774
U.S. government securities	251		—		(3		)	248
Total	$	2,763,321	$	8,480	$	(34,050	)	$	2,737,751

The following table provides the proceeds and gross realized gains and losses on sales of debt securities available for sale as well as other securities gains and losses for the periods indicated:



	Three Months Ended					Six Months Ended
	June 30,					June 30,
	2018			2017		2018			2017
	(in thousands)
Proceeds from sales of debt securities available for sale	$	12,569		$	—	$	32,330		$	—

Gross realized gains from sales of debt securities available for sale	$	87		$	—	$	235		$	—
Gross realized losses from sales of debt securities available for sale	(83		)	—		(129		)	—
Other securities losses, net (1)	(37		)	—		(117		)	—
Investment securities losses, net	$	(33	)	$	—	$	(11	)	$	—

__________

(1) Other securities losses, net includes net unrealized loss activity associated with equity securities. There were no sales of equity securities during the periods presented.

The scheduled contractual maturities of debt securities available for sale at June 30, 2018 are presented as follows:



	June 30, 2018
	Amortized Cost		Fair Value
	(in thousands)
Due within one year	$	127,209	$	127,133
Due after one year through five years	620,100		609,400
Due after five years through ten years	885,040		862,508
Due after ten years	1,083,696		1,047,167
Total debt securities available for sale	$	2,716,045	$	2,646,208

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:



	June 30, 2018
	(in thousands)
Washington and Oregon State to secure public deposits	$	244,565
Federal Reserve Bank to secure borrowings	52,370
Other securities pledged	93,194
Total securities pledged as collateral	$	390,129

The following table shows the gross unrealized losses and fair value of the Company’s debt securities available for sale 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 June 30, 2018 and December 31, 2017:



	Less than 12 Months					12 Months or More					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
June 30, 2018	(in thousands)
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	906,188	$	(22,365	)	$	722,422	$	(33,989	)	$	1,628,610	$	(56,354	)
State and municipal securities	306,897		(5,536		)	76,988		(4,340		)	383,885		(9,876		)
U.S. government agency and government-sponsored enterprise securities	261,185		(4,942		)	109,734		(2,286		)	370,919		(7,228		)
U.S. government securities	247		(4		)	—		—			247		(4		)
Total	$	1,474,517	$	(32,847	)	$	909,144	$	(40,615	)	$	2,383,661	$	(73,462	)
December 31, 2017
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	816,678	$	(6,710	)	$	717,211	$	(20,616	)	$	1,533,889	$	(27,326	)
State and municipal securities	220,019		(1,723		)	75,172		(2,236		)	295,191		(3,959		)
U.S. government agency and government-sponsored enterprise securities	184,046		(1,006		)	155,983		(1,756		)	340,029		(2,762		)
U.S. government securities	249		(3		)	—		—			249		(3		)
Total	$	1,220,992	$	(9,442	)	$	948,366	$	(24,608	)	$	2,169,358	$	(34,050	)

At June 30, 2018, there were 452 U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations securities in an unrealized loss position, of which 129 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 upon maturity, the Company does not consider these investments to be other-than-temporarily impaired at June 30, 2018.

At June 30, 2018, there were 422 state and municipal government securities in an unrealized loss position, of which 73 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 June 30, 2018, 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 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 June 30, 2018.

At June 30, 2018, there were 48 U.S. government agency and government-sponsored enterprise securities in an unrealized loss position, of which 12 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 June 30, 2018.

At June 30, 2018, there was one U.S. government security in an unrealized loss position, which was not 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 this investment falls within the yield curve and its 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 June 30, 2018.