Securities (Tables)

3 Months Ended

Mar. 31, 2015

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, 2015
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	1,093,576	$	13,765	$	(4,641	)	$	1,102,700
State and municipal securities	486,969		15,434		(732		)	501,671
U.S. government agency and government-sponsored enterprise securities	375,230		2,551		(983		)	376,798
U.S. government securities	20,918		—		(140		)	20,778
Other securities	5,284		40		(112		)	5,212
Total	$	1,981,977	$	31,790	$	(6,608	)	$	2,007,159
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

Schedule of gross realized gains and losses on sales and calls of securities available for sale

The following table provides the gross realized gains and losses on the sales of securities for the periods indicated:

	Three Months Ended
	March 31,
	2015			2014
	(in thousands)
Gross realized gains	$	730		$	223
Gross realized losses	(9		)	—
Net realized gains	$	721		$	223

Schedule of Contractual Maturities of Investment Securities Available for Sale

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

	March 31, 2015
	Amortized Cost		Fair Value
	(in thousands)
Due within one year	$	15,480	$	15,601
Due after one year through five years	404,752		406,989
Due after five years through ten years	526,230		534,584
Due after ten years	1,030,231		1,044,773
Other securities with no stated maturity	5,284		5,212
Total investment securities available-for-sale	$	1,981,977	$	2,007,159

Carrying Value of Securities Pledged As Collateral

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:

	March 31, 2015
	(in thousands)
Washington and Oregon State to secure public deposits	$	323,771
Federal Reserve Bank to secure borrowings	36,945
Other securities pledged	156,385
Total securities pledged as collateral	$	517,101

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, 2015 and December 31, 2014:

	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, 2015
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	94,304	$	(634	)	$	213,050	$	(4,007	)	$	307,354	$	(4,641	)
State and municipal securities	45,809		(227		)	31,597		(505		)	77,406		(732		)
U.S. government agency and government-sponsored enterprise securities	999		(1		)	178,013		(982		)	179,012		(983		)
U.S. government securities	1,050		(1		)	19,728		(139		)	20,778		(140		)
Other securities	—		—			2,843		(112		)	2,843		(112		)
Total	$	142,162	$	(863	)	$	445,231	$	(5,745	)	$	587,393	$	(6,608	)
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	)