Investments

The amortized cost and fair value of securities available for sale are as follows:



	December 31, 2016
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Available for sale:
Mortgage-backed securities	$	196,406	$	929	$	(3,042	)	$	194,293
Utah Housing Corporation bonds	15,000		—		(690		)	14,310
Total	$	211,406	$	929	$	(3,732	)	$	208,603

	December 31, 2015
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Available for sale:
Mortgage-backed securities	$	196,402	$	1,370	$	(2,381	)	$	195,391

The following table summarizes the amount of gross unrealized losses for our mortgage-backed securities and Utah housing bonds and the estimated fair value by length of time the securities have been in an unrealized loss position:



	Less than 12 months					12 months or more					Total
	Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value
As of December 31, 2016:
Mortgage-backed securities	$	(2,423	)	$	129,549	$	(619	)	$	10,885	$	(3,042	)	$	140,434
Utah Housing Corporation bonds	(690		)	14,310		—			—		(690		)	14,310
Total	$	(3,113	)	$	143,859	$	(619	)	$	10,885	$	(3,732	)	$	154,744

As of December 31, 2015:
Mortgage-backed securities	$	(827	)	$	73,802	$	(1,554	)	$	39,271	$	(2,381	)	$	113,073

Our investment portfolio is comprised primarily of mortgage-backed securities issued by Ginnie Mae, Fannie Mae and Freddie Mac, with amortized costs of $101.2 million, $66.5 million, and $28.8 million, respectively, at December 31, 2016. We own these securities to meet our requirements under the Community Reinvestment Act. As of December 31, 2016, there were 48 of 84 separate mortgage-backed securities with unrealized losses in our investment portfolio. As of December 31, 2016, 21 of the 48 securities in a net loss position were issued under Ginnie Mae programs that carry a full faith and credit guarantee from the U.S. Government. The remaining securities in a net loss position carry a principal and interest guarantee by Fannie Mae. As of December 31, 2015, there were 35 of 74 separate mortgage-backed securities with unrealized losses in our investment portfolio. Fourteen of the 35 securities in a net loss position were issued by Ginnie Mae. We have the ability and the intent to hold these securities for a period of time sufficient for the market price to recover to at least the adjusted amortized cost of the security.

In December 2016, we invested in Utah Housing Corporation bonds for the purpose of complying with the Community Reinvestment Act. These bonds are Aa3 rated by Moody’s Investors Service. The amortized cost of the investment on the consolidated balance sheet at December 31, 2016 was $15 million. We have the intent and ability to hold these bonds for a period of time sufficient for the market price to recover to at least the adjusted amortized cost of the security.

As of December 31, 2016, the amortized cost and fair value of securities, by contractual maturities, are summarized below. Contractual maturities versus actual maturities may differ due to the effect of prepayments.



Year of Maturity	Amortized Cost		Estimated Fair Value
2038	$	278	$	303
2039	5,405		5,758
2042	15,344		14,621
2043	46,996		47,045
2044	37,970		37,876
2045	50,814		50,084
2046	39,599		38,606
2047	15,000		14,310
Total	$	211,406	$	208,603

The mortgage-backed securities have been pledged to the FRB as collateral against any advances and accrued interest under the Primary Credit lending program sponsored by the FRB. We had $188.0 million and $188.3 million par value of mortgage-backed securities pledged to this borrowing facility at December 31, 2016 and 2015, respectively, as discussed further in Note 9, “Borrowings.”