Investment Securities (Tables)

9 Months Ended

Sep. 30, 2015

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 September 30, 2015 and December 31, 2014 and the corresponding amounts of unrealized gains and losses therein:

(dollars in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
September 30, 2015
Available-for-Sale
U.S. Treasury	$	11,971	$	268	$	—		$	12,239
U.S. government-sponsored entities and agencies		642,681		2,350		(3,251	)		641,780
Mortgage-backed securities - Agency		1,127,175		15,617		(6,440	)		1,136,352
States and political subdivisions		383,001		9,133		(2,031	)		390,103
Pooled trust preferred securities		17,443		—		(10,812	)		6,631
Other securities		336,394		1,854		(5,460	)		332,788
Total available-for-sale securities	$	2,518,665	$	29,222	$	(27,994	)	$	2,519,893
Held-to-Maturity
U.S. government-sponsored entities and agencies	$	143,694	$	4,161	$	—		$	147,855
Mortgage-backed securities - Agency		17,782		724		—			18,506
States and political subdivisions		689,575		46,299		(59	)		735,815
Total held-to-maturity securities	$	851,051	$	51,184	$	(59	)	$	902,176
December 31, 2014
Available-for-Sale
U.S. Treasury	$	14,978	$	196	$	(8	)	$	15,166
U.S. government-sponsored entities and agencies		692,704		1,533		(8,286	)		685,951
Mortgage-backed securities - Agency		1,233,811		18,219		(10,368	)		1,241,662
States and political subdivisions		304,435		11,023		(917	)		314,541
Pooled trust preferred securities		17,965		—		(11,358	)		6,607
Other securities		365,235		2,338		(3,669	)		363,904
Total available-for-sale securities	$	2,629,128	$	33,309	$	(34,606	)	$	2,627,831
Held-to-Maturity
U.S. government-sponsored entities and agencies	$	167,207	$	6,279	$	—		$	173,486
Mortgage-backed securities - Agency		23,648		926		—			24,574
States and political subdivisions		653,199		52,753		(77	)		705,875
Total held-to-maturity securities	$	844,054	$	59,958	$	(77	)	$	903,935

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 nine months ended September 30, 2015 and 2014:

	Three Months Ended September 30,						Nine Months Ended September 30,
(dollars in thousands)	2015			2014			2015			2014
Proceeds from sales of available-for-sale securities	$	100,257		$	79,581		$	296,841		$	155,876
Proceeds from calls of available-for-sale securities		108,790			43,236			321,792			67,776
Total	$	209,047		$	122,817		$	618,633		$	223,652
Realized gains on sales of available-for-sale securities	$	1,315		$	2,666		$	4,112		$	5,015
Realized gains on calls of available-for-sale securities		99			151			479			151
Realized losses on sales of available-for-sale securities		(373	)		(6	)		(420	)		(43	)
Realized losses on calls of available-for-sale securities		—			(201	)		(15	)		(468	)
Other securities gains (losses) (1)		(180	)		103			(100	)		306
Net securities gains	$	861		$	2,713		$	4,056		$	4,961

(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.

	September 30, 2015				Weighted
(dollars in thousands)	Amortized		Fair		Average
Maturity	Cost		Value		Yield
Available-for-Sale
Within one year	$	38,653	$	38,826		2.53	%
One to five years		491,482		494,542		1.79
Five to ten years		475,672		477,916		2.41
Beyond ten years		1,512,858		1,508,609		2.54
Total	$	2,518,665	$	2,519,893		2.37	%
Held-to-Maturity
Within one year	$	10,392	$	10,743		6.53	%
One to five years		29,175		30,530		3.95
Five to ten years		200,190		207,483		3.55
Beyond ten years		611,294		653,420		5.49
Total	$	851,051	$	902,176		4.99	%

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 September 30, 2015 and December 31, 2014 by aggregated major security type and length of time in a continuous unrealized loss position:

	Less than 12 months					12 months or longer					Total
(dollars in thousands)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
September 30, 2015
Available-for-Sale
U.S. government-sponsored entities and agencies	$	98,681	$	(1,203	)	$	122,560	$	(2,048	)	$	221,241	$	(3,251	)
Mortgage-backed securities - Agency		188,275		(1,443	)		256,905		(4,997	)		445,180		(6,440	)
States and political subdivisions		101,370		(1,756	)		5,503		(275	)		106,873		(2,031	)
Pooled trust preferred securities		—		—			6,631		(10,812	)		6,631		(10,812	)
Other securities		104,254		(1,317	)		128,376		(4,143	)		232,630		(5,460	)
Total available-for-sale	$	492,580	$	(5,719	)	$	519,975	$	(22,275	)	$	1,012,555	$	(27,994	)
Held-to-Maturity
States and political subdivisions	$	15,367	$	(59	)	$	—	$	—		$	15,367	$	(59	)
Total held-to-maturity	$	15,367	$	(59	)	$	—	$	—		$	15,367	$	(59	)
December 31, 2014
Available-for-Sale
U.S. Treasury	$	9,524	$	(8	)	$	—	$	—		$	9,524	$	(8	)
U.S. government-sponsored entities and agencies		180,488		(563	)		257,914		(7,723	)		438,402		(8,286	)
Mortgage-backed securities - Agency		31,304		(122	)		386,788		(10,246	)		418,092		(10,368	)
States and political subdivisions		41,481		(288	)		9,534		(629	)		51,015		(917	)
Pooled trust preferred securities		—		—			6,607		(11,358	)		6,607		(11,358	)
Other securities		115,973		(906	)		95,344		(2,763	)		211,317		(3,669	)
Total available-for-sale	$	378,770	$	(1,887	)	$	756,187	$	(32,719	)	$	1,134,957	$	(34,606	)
Held-to-Maturity
States and political subdivisions	$	6,171	$	(77	)	$	—	$	—		$	6,171	$	(77	)
Total held-to-maturity	$	6,171	$	(77	)	$	—	$	—		$	6,171	$	(77	)

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 September 30, 2015 (dollars in thousands)	Class		Lowest Credit Rating (1)		Amortized Cost		Fair Value		Unrealized Gain/ (Loss)			Realized Losses 2015		# 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	$	3,541	$	223	$	(3,318	)	$	—	25/41		33.3	%		7.5	%		0.0	%
Pretsl XXVII LTD		B		B		4,446		2,517		(1,929	)		—	34/45		20.5	%		4.2	%		41.6	%
Trapeza Ser 13A		A2A		BB+		9,456		3,891		(5,565	)		—	50/59		12.1	%		5.1	%		52.1	%
						17,443		6,631		(10,812	)		—
Single Issuer trust preferred securities:
Fleet Cap Tr V (BOA)				BB+		3,386		3,238		(148	)		—
JP Morgan Chase Cap XIII				BBB-		4,753		4,275		(478	)		—
NB-Global				BB+		764		925		161			—
Chase Cap II				BBB-		804		862		58			—
						9,707		9,300		(407	)		—
Total					$	27,150	$	15,931	$	(11,219	)	$	—

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

Securities with Other-than-Temporary-Impairment

The following table details the remaining securities with other-than-temporary-impairment, their credit rating at September 30, 2015, and the related life-to-date credit losses recognized in earnings:

							Amount of other-than-temporary impairment recognized  in earnings
(dollars in thousands)	Vintage		Lowest Credit Rating (1)		Amortized Cost		Nine Months Ended September 30,				Life-to date
							2015		2014
Reg Div Funding		2004		D	$	3,541	$	—	$	—	$	5,685
Limited partnership						765		—		100		100
Total					$	4,306	$	—	$	100	$	5,785

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