Securities (Tables)

9 Months Ended

Sep. 30, 2013

Available-for-sale Securities [Abstract]

Securities Available for Sale

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)
September 30, 2013
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	866,128	$	12,538	$	(16,997	)	$	861,669
State and municipal securities	344,053		13,824		(2,982		)	354,895
U.S. government agency and government-sponsored enterprise securities	335,989		483		(8,942		)	327,530
U.S. government securities	21,074		—		(657		)	20,417
Other securities	5,279		27		(166		)	5,140
Total	$	1,572,523	$	26,872	$	(29,744	)	$	1,569,651
December 31, 2012
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	561,076	$	16,719	$	(5,426	)	$	572,369
State and municipal securities	265,070		20,893		(388		)	285,575
U.S. government agency and government-sponsored enterprise securities	120,085		851		(435		)	120,501
U.S. government securities	19,804		39		(15		)	19,828
Other securities	3,324		104		(36		)	3,392
Total	$	969,359	$	38,606	$	(6,300	)	$	1,001,665

Schedule of Contractual Maturities of Investment Securities Available for Sale

The scheduled contractual maturities of investment securities available for sale at September 30, 2013 are presented as follows:

	September 30, 2013
	Amortized Cost		Fair Value
	(in thousands)
Due within one year	$	23,249	$	23,493
Due after one year through five years	278,538		278,715
Due after five years through ten years	463,423		459,080
Due after ten years	802,034		803,223
Other securities with no stated maturity	5,279		5,140
Total investment securities available-for-sale	$	1,572,523	$	1,569,651

Carrying Value of Securities Pledged As Collateral

The following table summarizes, as of September 30, 2013, 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	$	267,646
To Federal Reserve Bank to secure borrowings	44,526
Other securities pledged	43,325
Total securities pledged as collateral	$	355,497

Summary of Gross Unrealized Losses and Fair Value of the Investments with Unrealized Losses

The following table shows 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 September 30, 2013 and December 31, 2012:

	Less than 12 Months					12 Months or More					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
	(in thousands)
September 30, 2013
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	385,222	$	(12,567	)	$	64,044	$	(4,430	)	$	449,266	$	(16,997	)
State and municipal securities	101,176		(2,935		)	807		(47		)	101,983		(2,982		)
U.S. government agency and government-sponsored enterprise securities	290,257		(8,942		)	—		—			290,257		(8,942		)
U.S. government securities	20,217		(657		)	—		—			20,217		(657		)
Other securities	2,286		(24		)	2,813		(142		)	5,099		(166		)
Total	$	799,158	$	(25,125	)	$	67,664	$	(4,619	)	$	866,822	$	(29,744	)
December 31, 2012
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	167,739	$	(5,090	)	$	12,204	$	(336	)	$	179,943	$	(5,426	)
State and municipal securities	20,413		(383		)	210		(5		)	20,623		(388		)
U.S. government agency and government-sponsored enterprise securities	56,600		(435		)	—		—			56,600		(435		)
U.S. government securities	9,914		(15		)	—		—			9,914		(15		)
Other securities	—		—			964		(36		)	964		(36		)
Total	$	254,666	$	(5,923	)	$	13,378	$	(377	)	$	268,044	$	(6,300	)