Securities Available for Sale

Securities available for sale at December 31, 2017 and 2016 are summarized as follows (in thousands):



	2017
	Amortized cost		Gross unrealized gains	Gross unrealized losses		Fair value
Agency obligations	$	19,014	—	(9	)	19,005
Mortgage-backed securities	993,548		4,914	(10,095	)	988,367
State and municipal obligations	3,259		129	—		3,388
Corporate obligations	26,047		359	(12	)	26,394
Equity securities	417		241	—		658
	$	1,042,285	5,643	(10,116	)	1,037,812



	2016
	Amortized cost		Gross unrealized gains	Gross unrealized losses		Fair value
U.S. Treasury obligations	$	7,995	13	—		8,008
Agency obligations	57,123		90	(25	)	57,188
Mortgage-backed securities	952,992		7,249	(8,380	)	951,861
State and municipal obligations	3,727		19	(3	)	3,743
Corporate obligations	19,013		35	(11	)	19,037
Equity securities	397		152	—		549
	$	1,041,247	7,558	(8,419	)	1,040,386

Securities available for sale having a carrying value of $939.4 million and $720.4 million at December 31, 2017 and 2016, respectively, are pledged to secure other borrowings and securities sold under repurchase agreements.

The amortized cost and fair value of securities available for sale at December 31, 2017, by contractual maturity, are shown below (in thousands). Expected maturities may differ from contractual maturities due to prepayment or early call privileges of the issuer.



	2017
	Amortized cost		Fair value
Due in one year or less	$	20,406	20,390
Due after one year through five years	3,009		3,048
Due after five years through ten years	24,905		25,349
	$	48,320	48,787

Mortgage-backed securities totaling $993.5 million at amortized cost and $988.4 million at fair value are excluded from the table above as their expected lives are expected to be shorter than the contractual maturity date due to principal prepayments. Also excluded from the table above are equity securities of $417,000 at amortized cost and $658,000 at fair value.

During 2017, there were no sales or calls of securities from the available for sale portfolio. For the 2016 period, proceeds from the sale of securities available for sale were $3.4 million resulting in gross gains of $95,000 and gross losses of $45,000; there were no calls of securities from the available for sale portfolio for the year ended December 31, 2016.

For the years ended December 31, 2017 and 2016, the Company did not incur an other-than-temporary impairment charge on securities available for sale.

The following table represents the Company’s disclosure on securities available for sale with temporary impairment (in thousands):



	December 31, 2017 Unrealized Losses
	Less than 12 months				12 months or longer			Total
	Fair value		Gross unrealized losses		Fair value	Gross unrealized losses		Fair value	Gross unrealized losses
Agency obligations	$	12,006	(8	)	6,999	(1	)	19,005	(9	)
Mortgage-backed securities	420,746		(3,936	)	235,056	(6,159	)	655,802	(10,095	)
Corporate obligations	—		—		989	(12	)	989	(12	)
	$	432,752	(3,944	)	243,044	(6,172	)	675,796	(10,116	)



	December 31, 2016 Unrealized Losses
	Less than 12 months				12 months or longer			Total
	Fair value		Gross unrealized losses		Fair value	Gross unrealized losses		Fair value	Gross unrealized losses
Agency obligations	$	14,000	(25	)	—	—		14,000	(25	)
Mortgage-backed securities	553,629		(8,377	)	65	(3	)	553,694	(8,380	)
State and municipal obligations	661		(3	)	—	—		661	(3	)
Corporate obligations	—				990	(11	)	990	(11	)
	$	568,290	(8,405	)	1,055	(14	)	569,345	(8,419	)

The Company estimates the loss projections for each non-agency mortgage-backed security by stressing the individual loans collateralizing the security and applying a range of expected default rates, loss severities, and prepayment speeds in conjunction with the underlying credit enhancement for each security. Based on specific assumptions about collateral and vintage, a range of possible cash flows was identified to determine whether other-than-temporary impairment existed during the year ended December 31, 2017. Based on its detailed review of the securities available for sale portfolio, the Company believes that as of December 31, 2017, securities with unrealized loss positions shown above do not represent impairments that are other-than-temporary. The Company does not have the intent to sell securities in a temporary loss position at December 31, 2017, nor is it more likely than not that the Company will be required to sell the securities before the anticipated recovery.

The number of securities in an unrealized loss position as of December 31, 2017 totaled 122, compared with 87 at December 31, 2016. There were two private label mortgage-backed securities in an unrealized loss position at December 31, 2017, with an amortized cost of $99,000 and unrealized losses totaling $2,000. Both private label mortgage-backed securities were investment grade at December 31, 2017.