Securities (Tables)

3 Months Ended

Mar. 31, 2014

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)
March 31, 2014
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	919,299	$	10,339	$	(17,340	)	$	912,298
State and municipal securities	363,983		12,472		(2,775		)	373,680
U.S. government agency and government-sponsored enterprise securities	335,151		477		(7,642		)	327,986
U.S. government securities	21,088		1		(786		)	20,303
Other securities	5,284		25		(206		)	5,103
Total	$	1,644,805	$	23,314	$	(28,749	)	$	1,639,370
December 31, 2013
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	961,442	$	10,640	$	(23,674	)	$	948,408
State and municipal securities	357,013		11,450		(3,993		)	364,470
U.S. government agency and government-sponsored enterprise securities	335,671		434		(10,066		)	326,039
U.S. government securities	21,081		—		(967		)	20,114
Other securities	5,284		27		(231		)	5,080
Total	$	1,680,491	$	22,551	$	(38,931	)	$	1,664,111

Schedule of Contractual Maturities of Investment Securities Available for Sale

The scheduled contractual maturities of investment securities available for sale at March 31, 2014 are presented as follows:

	March 31, 2014
	Amortized Cost		Fair Value
	(in thousands)
Due within one year	$	23,252	$	23,415
Due after one year through five years	337,507		336,477
Due after five years through ten years	434,217		431,506
Due after ten years	844,545		842,869
Other securities with no stated maturity	5,284		5,103
Total investment securities available-for-sale	$	1,644,805	$	1,639,370

Carrying Value of Securities Pledged As Collateral

The following table summarizes, as of March 31, 2014, 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)
Washington and Oregon State to secure public deposits	$	278,061
Federal Reserve Bank to secure borrowings	42,631
Other securities pledged	43,038
Total securities pledged as collateral	$	363,730

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 March 31, 2014 and December 31, 2013:

	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, 2014
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	399,830	$	(7,290	)	$	112,690	$	(10,050	)	$	512,520	$	(17,340	)
State and municipal securities	88,065		(1,791		)	17,748		(984		)	105,813		(2,775		)
U.S. government agency and government-sponsored enterprise securities	251,196		(6,026		)	28,810		(1,616		)	280,006		(7,642		)
U.S. government securities	19,253		(786		)	—		—			19,253		(786		)
Other securities	2,270		(45		)	2,795		(161		)	5,065		(206		)
Total	$	760,614	$	(15,938	)	$	162,043	$	(12,811	)	$	922,657	$	(28,749	)
December 31, 2013
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	492,921	$	(10,991	)	$	121,303	$	(12,684	)	$	614,224	$	(23,675	)
State and municipal securities	112,400		(3,069		)	13,815		(923		)	126,215		(3,992		)
U.S. government agency and government-sponsored enterprise securities	260,001		(8,063		)	28,447		(2,003		)	288,448		(10,066		)
U.S. government securities	20,114		(967		)	—		—			20,114		(967		)
Other securities	2,257		(58		)	2,783		(173		)	5,040		(231		)
Total	$	887,693	$	(23,148	)	$	166,348	$	(15,783	)	$	1,054,041	$	(38,931	)