Securities

The following tables provide the amortized cost and fair values of securities at March 31, 2017 and December 31, 2016.

Table 37: Reconciliation of Amortized Cost to Fair Value of Securities Available for Sale



Securities Available for Sale	March 31, 2017
	Amortized Cost		Gross Unrealized				Fair Value
(In Millions)	Amortized Cost		Gains		Losses		Fair Value
U.S. Government	$	6,815.5	$	27.9	$	13.2	$	6,830.2
Obligations of States and Political Subdivisions	953.2		0.2		1.9		951.5
Government Sponsored Agency	17,947.4		52.6		63.6		17,936.4
Non-U.S. Government	219.8		—		1.7		218.1
Corporate Debt	3,578.0		3.6		22.6		3,559.0
Covered Bonds	887.3		1.1		3.5		884.9
Sub-Sovereign, Supranational and Non-U.S. Agency Bonds	1,761.0		3.1		2.8		1,761.3
Other Asset-Backed	2,349.0		4.4		1.5		2,351.9
Auction Rate	4.6		—		0.3		4.3
Commercial Mortgage-Backed	459.1		—		2.9		456.2
Other	43.8		—		—		43.8
Total	$	35,018.7	$	92.9	$	114.0	$	34,997.6



Securities Available for Sale	December 31, 2016
	Amortized Cost		Gross Unrealized				Fair Value
(In Millions)	Amortized Cost		Gains		Losses		Fair Value
U.S. Government	$	7,514.5	$	22.4	$	14.3	$	7,522.6
Obligations of States and Political Subdivisions	890.8		—		5.6		885.2
Government Sponsored Agency	17,914.1		49.3		70.6		17,892.8
Non-U.S. Government	420.0		—		2.1		417.9
Corporate Debt	3,787.4		2.6		24.8		3,765.2
Covered Bonds	1,148.6		0.8		5.5		1,143.9
Sub-Sovereign, Supranational and Non-U.S. Agency Bonds	1,343.6		0.9		3.8		1,340.7
Other Asset-Backed	2,083.7		2.7		1.3		2,085.1
Auction Rate	5.0		—		0.3		4.7
Commercial Mortgage-Backed	474.1		—		2.5		471.6
Other	50.1		—		—		50.1
Total	$	35,631.9	$	78.7	$	130.8	$	35,579.8

Table 38: Reconciliation of Amortized Cost to Fair Value of Securities Held to Maturity



Securities Held to Maturity	March 31, 2017
	Amortized Cost		Gross Unrealized				Fair Value
(In Millions)	Amortized Cost		Gains		Losses		Fair Value
U.S Government	$	6.0	$	—	$	—	$	6.0
Obligations of States and Political Subdivisions	49.0		2.6		—		51.6
Government Sponsored Agency	6.8		0.5		—		7.3
Corporate Debt	252.6		0.1		0.4		252.3
Covered Bonds	2,295.6		11.6		2.7		2,304.5
Non-U.S. Government	3,282.6		6.6		0.4		3,288.8
Certificates of Deposit	306.5		—		—		306.5
Sub-Sovereign, Supranational and Non-U.S. Agency Bonds	2,422.3		10.8		1.3		2,431.8
Other Asset-Backed	186.4		1.6		—		188.0
Other	130.6		—		34.0		96.6
Total	$	8,938.4	$	33.8	$	38.8	$	8,933.4



Securities Held to Maturity	December 31, 2016
	Amortized Cost		Gross Unrealized				Fair Value
(In Millions)	Amortized Cost		Gains		Losses		Fair Value
U.S Government	$	15.0	$	—	$	—	$	15.0
Obligations of States and Political Subdivisions	63.6		2.7		—		66.3
Government Sponsored Agency	7.4		0.5		—		7.9
Corporate Debt	231.2		0.2		0.4		231.0
Covered Bonds	2,051.6		10.1		3.7		2,058.0
Non-U.S. Government	3,517.5		4.9		2.3		3,520.1
Certificates of Deposit	606.0		0.2		0.1		606.1
Sub-Sovereign, Supranational and Non-U.S. Agency Bonds	2,154.7		10.5		2.8		2,162.4
Other Asset-Backed	143.4		0.1		—		143.5
Other	130.7		—		35.9		94.8
Total	$	8,921.1	$	29.2	$	45.2	$	8,905.1

Securities held to maturity consist of debt securities that management intends to, and Northern Trust has the ability to, hold until maturity.

The following table provides the remaining maturity of securities as of March 31, 2017.

Table 39: Remaining Maturity of Securities Available for Sale and Held to Maturity



	March 31, 2017
(In Millions)	Amortized Cost		Fair Value
Available for Sale
Due in One Year or Less	$	6,665.1	$	6,660.1
Due After One Year Through Five Years	21,136.2		21,124.3
Due After Five Years Through Ten Years	6,015.5		6,017.7
Due After Ten Years	1,201.9		1,195.5
Total	35,018.7		34,997.6
Held to Maturity
Due in One Year or Less	2,914.6		2,916.9
Due After One Year Through Five Years	5,764.1		5,783.4
Due After Five Years Through Ten Years	201.2		200.2
Due After Ten Years	58.5		32.9
Total	$	8,938.4	$	8,933.4

Note: Mortgage-backed and asset-backed securities are included in the above table taking into account anticipated future prepayments.

Investment Security Gains / Losses. Net investment security losses of $0.3 million were recognized in the three months ended March 31, 2017, which include $0.1 million of charges related to the other-than-temporary impairment (OTTI) of certain Community Reinvestment ACT (CRA) eligible held to maturity securities. Net investment security gains of $0.3 million were recognized in the three months ended March 31, 2016. For three months ended March 31, 2017, proceeds of $541.3 million were received from the sale of securities resulting in gross realized losses of $0.2 million. For the three months ended March 31, 2016, proceeds of $513.6 million were received from the sale of securities, resulting in realized gross gains of $0.3 million.

Securities with Unrealized Losses. The following tables provide information regarding securities that had been in a continuous unrealized loss position for less than twelve months and for twelve months or longer as of March 31, 2017 and December 31, 2016.

Table 40: Securities with Unrealized Losses



Securities with Unrealized Losses as of March 31, 2017	Less than 12 Months				12 Months or Longer				Total
(In Millions)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
U.S. Government	$	1,701.3	$	13.2	$	—	$	—	$	1,701.3	$	13.2
Obligations of States and Political Subdivisions	750.1		1.9		—		—		750.1		1.9
Government Sponsored Agency	7,455.5		51.5		2,433.8		12.1		9,889.3		63.6
Non-U.S. Government	1,729.3		2.1		—		—		1,729.3		2.1
Corporate Debt	1,555.2		9.6		807.3		13.4		2,362.5		23.0
Covered Bonds	829.3		6.0		139.2		0.2		968.5		6.2
Sub-Sovereign, Supranational and Non-U.S. Agency Bonds	1,089.2		3.4		249.3		0.7		1,338.5		4.1
Other Asset-Backed	714.5		1.5		—		—		714.5		1.5
Auction Rate	0.4		0.1		3.8		0.2		4.2		0.3
Commercial Mortgage-Backed	439.3		2.9		—		—		439.3		2.9
Other	48.4		14.1		51.6		19.9		100.0		34.0
Total	$	16,312.5	$	106.3	$	3,685.0	$	46.5	$	19,997.5	$	152.8



Securities with Unrealized Losses as of December 31, 2016	Less than 12 Months				12 Months or Longer				Total
(In Millions)	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
U.S. Government	$	1,603.0	$	14.3	$	—	$	—	$	1,603.0	$	14.3
Obligations of States and Political Subdivisions	865.3		5.6		—		—		865.3		5.6
Government Sponsored Agency	8,252.5		58.5		2,121.0		12.1		10,373.5		70.6
Non-U.S. Government	2,957.1		4.4		—		—		2,957.1		4.4
Corporate Debt	1,601.7		11.2		1,054.4		14.0		2,656.1		25.2
Covered Bonds	809.0		8.6		138.9		0.6		947.9		9.2
Sub-Sovereign, Supranational and Non-U.S. Agency Bonds	1,136.1		5.7		249.1		0.9		1,385.2		6.6
Other Asset-Backed	584.3		1.3		—		—		584.3		1.3
Certificates of Deposit	81.4		0.1		—		—		81.4		0.1
Auction Rate	0.4		0.1		4.3		0.2		4.7		0.3
Commercial Mortgage-Backed	471.5		2.5		—		—		471.5		2.5
Other	50.5		17.9		59.7		18.0		110.2		35.9
Total	$	18,412.8	$	130.2	$	3,627.4	$	45.8	$	22,040.2	$	176.0

As of March 31, 2017, 1,074 securities with a combined fair value of $20.0 billion were in an unrealized loss position, with their unrealized losses totaling $152.8 million. Unrealized losses of $63.6 million related to government sponsored agency securities are primarily attributable to changes in market interest rates since their purchase. Unrealized losses of $23.0 million within corporate debt securities primarily reflect widened credit spreads and higher market rates since purchase; 35% of the corporate debt portfolio is backed by guarantees provided by U.S. and non-U.S. governmental entities.

The majority of the $34.0 million of unrealized losses in securities classified as “other” at March 31, 2017, related to securities primarily purchased at a premium or par by Northern Trust for compliance with the CRA. Unrealized losses on these CRA-related securities were attributable to yields that were below market rates for the purpose of supporting institutions and programs that benefit low- to moderate- income communities within Northern Trust’s market area. Unrealized losses of $0.3 million related to auction rate securities primarily reflected reduced market liquidity as a majority of auctions continued to fail, preventing holders from liquidating their investments at par. The remaining unrealized losses on Northern Trust’s securities portfolio as of March 31, 2017, were attributable to changes in overall market interest rates, increased credit spreads or reduced market liquidity. As of March 31, 2017, Northern Trust did not intend to sell any investment in an unrealized loss position and it was more likely than not that Northern Trust would not be required to sell any such investment before the recovery of its amortized cost basis, which may be maturity.

Security impairment reviews are conducted quarterly to identify and evaluate securities that have indications of possible OTTI. A determination as to whether a security’s decline in market value is other-than-temporary takes into consideration numerous factors and the relative significance of any single factor can vary by security. Factors Northern Trust considers in determining whether impairment is other-than-temporary include, but are not limited to: the length of time the security has been impaired; the severity of the impairment; the cause of the impairment and the financial condition and near-term prospects of the issuer; activity in the market of the issuer, which may indicate adverse credit conditions; Northern Trust’s intent regarding the sale of the security as of the balance sheet date; and the likelihood that it will not be required to sell the security for a period of time sufficient to allow for the recovery of the security’s amortized cost basis. For each security meeting the requirements of Northern Trust’s internal screening process, an extensive review is conducted to determine if OTTI has occurred.

While all securities are considered, the process for identifying credit impairment within CRA-eligible mortgage-backed securities incorporates an expected loss approach using discounted cash flows on the underlying collateral pools. To evaluate whether an unrealized loss on CRA-eligible mortgage-backed securities is other-than-temporary, a calculation of the security’s present value is made using current pool data, the current delinquency pipeline, default rates and loan loss severities based on the historical performance of the mortgage pools, and Northern Trust’s outlook for the housing market and the overall economy. If the present value of the collateral pools was found to be less than the current amortized cost of the security, a credit-related OTTI loss would be recorded in earnings equal to the difference between the two amounts.

Impairments of CRA-eligible mortgage-backed securities are influenced by a number of factors, including but not limited to, U.S. economic and housing market performance, pool credit enhancement level, year of origination and estimated credit quality of the collateral. The factors used in estimating losses related to CRA-eligible mortgage-backed securities vary by vintage of loan origination and collateral quality.

There were $0.1 million of OTTI losses recognized in the three months ended March 31, 2017 related to CRA-eligible mortgage-backed securities. There were no OTTI losses recognized during the three months ended March 31, 2016.

Credit Losses on Debt Securities. The table below provides the cumulative credit-related losses recognized in earnings on debt securities other-than-temporarily impaired.

Table 41: Cumulative Credit-Related Losses on Securities



	Three Months Ended March 31,
(In Millions)	2017		2016
Cumulative Credit-Related Losses on Securities Held — Beginning of Period	$	3.4	$	5.2
Plus: Losses on Newly Identified Impairments	—		—
Additional Losses on Previously Identified Impairments	0.1		—
Less: Current and Prior Period Losses on Securities Sold During the Period	—		—
Cumulative Credit-Related Losses on Securities Held — End of Period	$	3.5	$	5.2