Investment Securities (Tables)

6 Months Ended

Jun. 30, 2018

Summary of Amortized Cost and Estimated Fair Values of Available for Sale Securities

The amortized cost and estimated fair values of securities available for sale are summarized as follows.


	June 30, 2018
			Gross		Gross		Estimated		Cumulative
	Amortized		Unrealized		Unrealized		Fair		OTTI in
	Cost		Gains		Losses		Value		AOCI ⁽¹⁾
U.S. Treasury securities and obligations of U.S. Government corporations and agencies	$	144,867	$	8	$	1,060	$	143,815	$	0
State and political subdivisions		276,516		897		5,233		272,180		0
Residential mortgage-backed securities
Agency		913,926		766		24,562		890,130		0
Non-agency		4,306		487		0		4,793		86
Commercial mortgage-backed securities
Agency		513,212		127		11,936		501,403		0
Asset-backed securities		166,355		342		566		166,131		0
Trust preferred collateralized debt obligations		6,177		91		450		5,818		2,586
Single issue trust preferred securities		8,742		234		738		8,238		0
Other corporate securities		69,261		174		1,016		68,419		0

Total	$	2,103,362	$	3,126	$	45,561	$	2,060,927	$	2,672


	December 31, 2017
			Gross		Gross		Estimated		Cumulative
	Amortized		Unrealized		Unrealized		Fair		OTTI in
	Cost		Gains		Losses		Value		AOCI ⁽¹⁾
U.S. Treasury securities and obligations of U.S. Government corporations and agencies	$	114,735	$	385	$	362	$	114,758	$	0
State and political subdivisions		303,101		3,197		2,429		303,869		0
Residential mortgage-backed securities
Agency		821,857		2,096		9,360		814,593		0
Non-agency		4,969		543		0		5,512		86
Commercial mortgage-backed securities
Agency		457,107		1,059		3,309		454,857		0
Asset-backed securities		109,829		148		7		109,970		0
Trust preferred collateralized debt obligations		37,856		542		4,129		34,269		20,770
Single issue trust preferred securities		13,417		368		1,225		12,560		0
Other corporate securities		28,101		407		18		28,490		0
Marketable equity securities		9,712		179		13		9,878		0

Total	$	1,900,684	$	8,924	$	20,852	$	1,888,756	$	20,856

(1)	Non-credit related other-than-temporary impairment in accumulated other comprehensive income. Amounts are before-tax.

Summary of Securities Available for Sale in an Unrealized Loss Position

The following is a summary of securities available-for-sale which were in an unrealized loss position at June 30, 2018 and December 31, 2017.


	Less than 12 months				12 months or longer
	Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses
June 30, 2018
U.S. Treasury securities and obligations of U.S. Government corporations and agencies	$	116,482	$	964	$	22,771	$	97
State and political subdivisions		137,435		1,710		57,150		3,524
Residential mortgage-backed securities
Agency		664,630		16,051		190,576		8,511
Non-agency		0		0		0		0
Commercial mortgage-backed securities
Agency		415,526		10,289		69,225		1,647
Asset-backed securities		75,437		566		0		0
Trust preferred collateralized debt obligations		0		0		2,050		450
Single issue trust preferred securities		0		0		4,980		737
Other corporate securities		51,304		1,015		0		0

Total	$	1,460,814	$	30,595	$	346,752	$	14,966


	Less than 12 months				12 months or longer
	Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses
December 31, 2017
U.S. Treasury securities and obligations of U.S. Government corporations and agencies	$	36,678	$	230	$	22,920	$	132
State and political subdivisions		82,896		566		59,432		1,863
Residential mortgage-backed securities
Agency		460,414		4,621		182,482		4,739
Non-agency		0		0		0		0
Commercial mortgage-backed securities
Agency		282,858		2,386		70,763		923
Asset-backed securities		27,931		7		0		0
Trust preferred collateralized debt obligations		0		0		28,629		4,129
Single issue trust preferred securities		0		0		4,485		1,225
Other corporate securities		6,975		18		0		0
Marketable equity securities		0		0		363		13

Total	$	897,752	$	7,828	$	369,074	$	13,024

Summary of Gains or Losses on Proceeds from Maturities, Sales and Calls of Available for Sale Securities by Specific Identification Method

The realized losses relate to sales of securities within a rabbi trust for the payment of benefits under a deferred compensation plan for certain key officers of United and its subsidiaries.


	Three Months Ended June 30				Six Months Ended June 30
	2018		2017		2018		2017
Proceeds from sales and calls	$	75,157	$	468,506	$	174,860	$	567,304
Gross realized gains		58		845		1,221		1,059
Gross realized losses		85		82		1,397		82

Roll Forward of Credit Losses on Securities

Below is a progression of the credit losses on securities which United has recorded other-than-temporary charges. These charges were recorded through earnings and other comprehensive income.


	Three Months Ended June 30				Six Months Ended June 30
	2018		2017		2018			2017
Balance of cumulative credit losses at beginning of period	$	3,199	$	22,162	$	18,060		$	22,162
Reductions for securities sold or paid off during the period		0		0		(14,861	)		0

Balance of cumulative credit losses at end of period	$	3,199	$	22,162	$	3,199		$	22,162

Summary of Amortized Cost and Estimated Fair Values of Securities Held to Maturity

The amortized cost and estimated fair values of securities held to maturity are summarized as follows:


	June 30, 2018
			Gross		Gross		Estimated
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
U.S. Treasury securities and obligations of U.S. Government corporations and agencies	$	5,132	$	181	$	0	$	5,313
State and political subdivisions		5,798		9		0		5,807
Residential mortgage-backed securities
Agency		21		3		0		24
Single issue trust preferred securities		9,407		0		863		8,544
Other corporate securities		20		0		0		20

Total	$	20,378	$	193	$	863	$	19,708


	December 31, 2017
			Gross		Gross		Estimated
	Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
U.S. Treasury securities and obligations of U.S. Government corporations and agencies	$	5,187	$	308	$	0	$	5,495
State and political subdivisions		5,797		10		0		5,807
Residential mortgage-backed securities
Agency		23		3		0		26
Single issue trust preferred securities		9,401		0		731		8,670
Other corporate securities		20		0		0		20

Total	$	20,428	$	321	$	731	$	20,018

Summary of Equity Securities

Prior to the adoption of ASU No. 2016-01 on January 1, 2018, equity securities were included in available for sale securities.


	Three Months Ended June 30, 2018			Six Months Ended June 30, 2018
Net gains (losses) recognized during the period	$	(28	)	$	(64	)
Net gains (losses) recognized during the period on equity securities sold		(4	)		(2	)
Unrealized gains recognized during the period on equity securities still held at period end		11			50
Unrealized losses recognized during the period on equity securities still held at period end		35			112

Available-for-sale Securities [Member]

Summary of Maturities of Debt Securities Held to Maturity by Amortized Cost and Estimated Fair Value

Expected maturities may differ from contractual maturities because the issuers may have the right to call or prepay obligations without penalties.


	June 30, 2018				December 31, 2017
			Estimated				Estimated
	Amortized		Fair		Amortized		Fair
	Cost		Value		Cost		Value
Due in one year or less	$	68,381	$	68,272	$	50,311	$	50,212
Due after one year through five years		510,595		503,142		386,039		384,585
Due after five years through ten years		447,739		435,727		400,129		398,208
Due after ten years		1,076,647		1,053,786		1,054,493		1,045,873
Marketable equity securities		0		0		9,712		9,878

Total	$	2,103,362	$	2,060,927	$	1,900,684	$	1,888,756

Held-to-maturity Securities [Member]

Summary of Maturities of Debt Securities Held to Maturity by Amortized Cost and Estimated Fair Value

Expected maturities may differ from contractual maturities because the issuers may have the right to call or prepay obligations without penalties.


	June 30, 2018				December 31, 2017
			Estimated				Estimated
	Amortized		Fair		Amortized		Fair
	Cost		Value		Cost		Value
Due in one year or less	$	2,000	$	2,000	$	0	$	0
Due after one year through five years		7,290		7,478		9,344		9,660
Due after five years through ten years		8,092		7,610		5,663		5,343
Due after ten years		2,996		2,620		5,421		5,015

Total	$	20,378	$	19,708	$	20,428	$	20,018