Investment Securities (Tables)

6 Months Ended

Jun. 30, 2017

Investments, Debt and Equity Securities [Abstract]

Amortized Cost and Fair Value of Available-for-Sale and Held-to-Maturity Investment Securities Portfolio

The following table summarizes the amortized cost and fair value of the available-for-sale and held-to-maturity investment securities portfolio at June 30, 2017 and December 31, 2016 and the corresponding amounts of unrealized gains and losses therein:


	Amortized		Unrealized		Unrealized			Fair
(dollars in thousands)	Cost		Gains		Losses			Value
June 30, 2017
Available-for-Sale
U.S. Treasury	$	5,470	$	164	$	—		$	5,634
U.S. government-sponsored entities and agencies		586,175		211		(5,762	)		580,624
Mortgage-backed securities—Agency		1,473,369		6,204		(17,462	)		1,462,111
States and political subdivisions		426,400		8,027		(2,553	)		431,874
Pooled trust preferred securities		16,807		—		(8,710	)		8,097
Other securities		325,788		2,444		(2,234	)		325,998

Total available-for-sale securities	$	2,834,009	$	17,050	$	(36,721	)	$	2,814,338

Held-to-Maturity
Mortgage-backed securities—Agency	$	8,576	$	308	$	—		$	8,884
States and political subdivisions		686,563		53,916		—			740,479

Total held-to-maturity securities	$	695,139	$	54,224	$	—		$	749,363

December 31, 2016
Available-for-Sale
U.S. Treasury	$	6,963	$	140	$	—		$	7,103
U.S. government-sponsored entities and agencies		506,234		113		(12,391	)		493,956
Mortgage-backed securities—Agency		1,551,465		6,923		(33,369	)		1,525,019
States and political subdivisions		446,003		4,183		(13,502	)		436,684
Pooled trust preferred securities		17,011		—		(8,892	)		8,119
Other securities		331,001		1,074		(5,782	)		326,293

Total available-for-sale securities	$	2,858,677	$	12,433	$	(73,936	)	$	2,797,174

Held-to-Maturity
U.S. government-sponsored entities and agencies	$	40,131	$	427	$	—		$	40,558
Mortgage-backed securities—Agency		10,640		300		—			10,940
States and political subdivisions		694,319		38,915		(560	)		732,674

Total held-to-maturity securities	$	745,090	$	39,642	$	(560	)	$	784,172

Schedule of Proceeds from Sales or Calls and Realized Gain and Losses of Available-for-Sale Investment Securities and Other Securities

Proceeds from sales or calls of available-for-sale investment securities, the resulting realized gains and realized losses, and other securities gains or losses were as follows for the three and six months ended June 30, 2017 and 2016:


	Three Months Ended						Six Months Ended
	June 30,						June 30,
(dollars in thousands)	2017			2016			2017			2016
Proceeds from sales of available-for-sale securities	$	152,689		$	30,801		$	186,277		$	107,451
Proceeds from calls of available-for-sale securities		60,600			239,998			71,120			364,309

Total	$	213,289		$	270,799		$	257,397		$	471,760

Realized gains on sales of available-for-sale securities	$	2,954		$	1,491		$	4,283		$	3,151
Realized gains on calls of available-for-sale securities		—			126			—			370
Realized losses on sales of available-for-sale securities		(13	)		(1	)		(43	)		(447	)
Realized losses on calls of available-for-sale securities		(7	)		(1	)		(8	)		(88	)
Other securities gains (losses) (1)		141			241			343			(24	)

Net securities gains (losses)	$	3,075		$	1,856		$	4,575		$	2,962

(1)	Other securities gains (losses) includes net realized gains or losses associated with trading securities and mutual funds.

Expected Maturities of Investment Securities Portfolio

Weighted average yield is based on amortized cost.

At June 30, 2017

(dollars in thousands)

Weighted

Amortized

Fair

Average

Maturity

Cost

Value

Yield

Available-for-Sale

Within one year

27,593

27,663

2.04

One to five years

355,595

356,174

2.14

Five to ten years

326,554

330,878

2.85

Beyond ten years

2,124,267

2,099,623

2.42

Total

2,834,009

2,814,338

2.43

Held-to-Maturity

Within one year

23,108

23,473

6.12

One to five years

73,901

77,005

4.46

Five to ten years

153,039

163,208

4.85

Beyond ten years

445,091

485,677

5.74

Total

695,139

749,363

5.42

Investment Securities with Unrealized Losses by Aggregated Major Security Type and Length of Time in Continuous Unrealized Loss Position

The following table summarizes the investment securities with unrealized losses at June 30, 2017 and December 31, 2016 by aggregated major security type and length of time in a continuous unrealized loss position:


	Less than 12 months					12 months or longer					Total
	Fair		Unrealized			Fair		Unrealized			Fair		Unrealized
(dollars in thousands)	Value		Losses			Value		Losses			Value		Losses
June 30, 2017
Available-for-Sale
U.S. government-sponsored entities and agencies	$	491,338	$	(5,762	)	$	—	$	—		$	491,338	$	(5,762	)
Mortgage-backed securities—Agency		928,155		(15,231	)		55,937		(2,231	)		984,092		(17,462	)
States and political subdivisions		116,598		(2,461	)		5,087		(92	)		121,685		(2,553	)
Pooled trust preferred securities		—		—			8,097		(8,710	)		8,097		(8,710	)
Other securities		97,380		(969	)		101,203		(1,265	)		198,583		(2,234	)

Total available-for-sale	$	1,633,471	$	(24,423	)	$	170,324	$	(12,298	)	$	1,803,795	$	(36,721	)

Held-to-Maturity
States and political subdivisions	$	466	$	—		$	—	$	—		$	466	$	—

Total held-to-maturity	$	466	$	—		$	—	$	—		$	466	$	—

December 31, 2016
Available-for-Sale
U.S. government-sponsored entities and agencies	$	432,192	$	(12,391	)	$	—	$	—		$	432,192	$	(12,391	)
Mortgage-backed securities—Agency		1,177,093		(30,295	)		57,636		(3,074	)		1,234,729		(33,369	)
States and political subdivisions		286,351		(13,247	)		4,919		(255	)		291,270		(13,502	)
Pooled trust preferred securities		—		—			8,119		(8,892	)		8,119		(8,892	)
Other securities		121,498		(2,734	)		126,539		(3,048	)		248,037		(5,782	)

Total available-for-sale	$	2,017,134	$	(58,667	)	$	197,213	$	(15,269	)	$	2,214,347	$	(73,936	)

Held-to-Maturity
States and political subdivisions	$	59,481	$	(560	)	$	—	$	—		$	59,481	$	(560	)

Total held-to-maturity	$	59,481	$	(560	)	$	—	$	—		$	59,481	$	(560	)

Trust Preferred Securities

The table below summarizes the relevant characteristics of our pooled trust preferred securities as well as our single issuer trust preferred securities that are included in the “other securities” category in this footnote. Each of the pooled trust preferred securities support a more senior tranche of security holders. All three pooled trust preferred securities have experienced credit defaults. However, two of these securities have excess subordination and are not other-than-temporarily-impaired as a result of their class hierarchy, which provides more loss protection.


Trust preferred securities June 30, 2017 (dollars in thousands)	Class		Lowest Credit Rating (1)		Amortized Cost		Fair Value		Unrealized Gain/ (Loss)			Realized Losses 2017		# of Issuers Currently Performing/ Remaining		Actual Deferrals and Defaults as a % of Original Collateral			Expected Defaults as a % of Remaining Performing Collateral			Excess Subordination as a % of Current Performing Collateral
Pooled trust preferred securities:
Reg Div Funding 2004		B-2		D	$	2,899	$	264	$	(2,635	)	$	—		22/37		32.1	%		7.4	%		0.0	%
Pretsl XXVII LTD		B		B		4,422		2,395		(2,027	)		—		35/44		16.7	%		3.9	%		46.5	%
Trapeza Ser 13A		A2A		BBB		9,486		5,438		(4,048	)		—		50/55		4.5	%		4.7	%		45.4	%

						16,807		8,097		(8,710	)		—
Single Issuer trust preferred securities:
Fleet Cap Tr V (BOA)				BB+		3,401		3,308		(93	)		—
JP Morgan Chase Cap XIII				BBB-		4,772		4,663		(109	)		—
NB-Global				BB+		794		946		152			—
Chase Cap II				BBB-		830		944		114			—

						9,797		9,861		64			—
Total					$	26,604	$	17,958	$	(8,646	)	$	—

(1)	Lowest rating for the security provided by any nationally recognized credit rating agency.