Securities (Tables)

6 Months Ended

Jun. 30, 2017

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)
June 30, 2017
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	1,438,875	$	3,478	$	(18,395	)	$	1,423,958
State and municipal securities	476,510		9,279		(2,696		)	483,093
U.S. government agency and government-sponsored enterprise securities	352,039		1,486		(1,287		)	352,238
U.S. government securities	251		—		(1		)	250
Other securities	5,284		70		(257		)	5,097
Total	$	2,272,959	$	14,313	$	(22,636	)	$	2,264,636
December 31, 2016
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	1,486,690	$	2,760	$	(23,718	)	$	1,465,732
State and municipal securities	473,914		6,343		(5,197		)	475,060
U.S. government agency and government-sponsored enterprise securities	332,348		1,065		(1,511		)	331,902
U.S. government securities	801		—		(1		)	800
Other securities	5,284		63		(264		)	5,083
Total	$	2,299,037	$	10,231	$	(30,691	)	$	2,278,577

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

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

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2017		2016		2017		2016
	(in thousands)
Proceeds from sales of available for sale securities	$	—	$	44,534	$	—	$	83,410
Gross realized gains	$	—	$	229	$	—	$	602
Gross realized losses	—		—		—		—
Net realized gains	$	—	$	229	$	—	$	602

Schedule of Contractual Maturities of Investment Securities Available for Sale

The scheduled contractual maturities of investment securities available for sale at June 30, 2017 are presented as follows:

	June 30, 2017
	Amortized Cost		Fair Value
	(in thousands)
Due within one year	$	99,775	$	99,740
Due after one year through five years	461,043		464,716
Due after five years through ten years	726,133		724,520
Due after ten years	980,724		970,563
Other securities with no stated maturity	5,284		5,097
Total investment securities available-for-sale	$	2,272,959	$	2,264,636

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:

	June 30, 2017
	(in thousands)
Washington and Oregon State to secure public deposits	$	244,580
Federal Reserve Bank to secure borrowings	54,877
Other securities pledged	122,932
Total securities pledged as collateral	$	422,389

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 June 30, 2017 and December 31, 2016:

	Less than 12 Months					12 Months or More					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
	(in thousands)
June 30, 2017
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	858,558	$	(12,683	)	$	180,212	$	(5,712	)	$	1,038,770	$	(18,395	)
State and municipal securities	108,038		(2,189		)	13,246		(507		)	121,284		(2,696		)
U.S. government agency and government-sponsored enterprise securities	194,738		(1,287		)	—		—			194,738		(1,287		)
U.S. government securities	251		(1		)	—		—			251		(1		)
Other securities	2,276		(39		)	2,737		(218		)	5,013		(257		)
Total	$	1,163,861	$	(16,199	)	$	196,195	$	(6,437	)	$	1,360,056	$	(22,636	)
December 31, 2016
U.S. government agency and government-sponsored enterprise mortgage-backed securities and collateralized mortgage obligations	$	1,029,116	$	(18,788	)	$	159,046	$	(4,930	)	$	1,188,162	$	(23,718	)
State and municipal securities	211,342		(5,064		)	3,384		(133		)	214,726		(5,197		)
U.S. government agency and government-sponsored enterprise securities	218,811		(1,511		)	—		—			218,811		(1,511		)
U.S. government securities	251		(1		)	—		—			251		(1		)
Other securities	2,263		(51		)	2,743		(213		)	5,006		(264		)
Total	$	1,461,783	$	(25,415	)	$	165,173	$	(5,276	)	$	1,626,956	$	(30,691	)