Impairment of Investment Securities (Tables)

12 Months Ended

Dec. 31, 2014

Impairment of Investment Securities Disclosure [Abstract]

Schedule of Unrealized Losses and Estimated Fair Values

The following table presents the gross unrealized losses and estimated fair values at December 31, 2014 by investment category and time frame for which the securities have been in a continuous unrealized loss position:

	Less Than 12 Months					12 Months or More					Total
	Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses
	(dollars in thousands)
Obligations of U.S. Government Agencies:
Mortgage-Backed Securities – Residential	$	2,318	$	(3	)	$	—	$	—		$	2,318	$	(3	)
Obligations of U.S. Government-Sponsored Enterprises:
Mortgage-Backed Securities – Residential	111,646		(419		)	368,706		(9,411		)	480,352		(9,830		)
Other Government-Sponsored Enterprises	112,473		(229		)	130,401		(1,079		)	242,874		(1,308		)
Obligations of States and Political Subdivisions	3,146		(43		)	—		—			3,146		(43		)
Pooled Trust Preferred Collateralized Debt Obligations	—		—			24,356		(13,236		)	24,356		(13,236		)
Total Securities Available for Sale	$	229,583	$	(694	)	$	523,463	$	(23,726	)	$	753,046	$	(24,420	)

At December 31, 2014, pooled trust preferred collateralized debt obligations accounted for 54% of unrealized losses due to changes in interest rates and the illiquid market for this type of investment. Fixed income securities issued by U.S. Government-sponsored enterprises comprised 46% of total unrealized losses due to changes in market interest rates. There were no equity securities in an unrealized loss position at December 31, 2014.

The following table presents the gross unrealized losses and estimated fair value at December 31, 2013 for available-for-sale and securities by investment category and time frame for which the securities had been in a continuous unrealized loss position:

	Less Than 12 Months					12 Months or More					Total
	Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses
	(dollars in thousands)
Obligations of U.S. Government Agencies:
Mortgage-Backed Securities – Residential	$	2,035	$	(59	)	$	—	$	—		$	2,035	$	(59	)
Obligations of U.S. Government-Sponsored Enterprises:
Mortgage-Backed Securities – Residential	632,231		(22,844		)	65,324		(4,319		)	697,555		(27,163		)
Other Government-Sponsored Enterprises	183,542		(1,448		)	24,501		(479		)	208,043		(1,927		)
Pooled Trust Preferred Collateralized Debt Obligations	2,401		(237		)	21,122		(18,280		)	23,523		(18,517		)
Total Securities Available for Sale	$	820,209	$	(24,588	)	$	110,947	$	(23,078	)	$	931,156	$	(47,666	)

Pooled Trust Preferred Collateralized Debt Obligations

The following table provides additional information related to our pooled trust preferred collateralized debt obligations as of December 31, 2014:

Deal	Class	Book Value		Estimated Fair Value		Unrealized Gain (Loss)			Moody’s/ Fitch Ratings	Number of Banks	Deferrals and Defaults as a % of Current Collateral		Excess Subordination as a % of Current Performing Collateral
(dollars in thousands)
Pre TSL IV	Mezzanine	$	1,830	$	1,326	$	(504	)	B1/BB	6	18.05	%	54.84	%
Pre TSL V	Mezzanine	60		130		70			C/-	3	100.00		0.00
Pre TSL VII	Mezzanine	2,779		2,987		208			Ca/-	14	49.68		0.00
Pre TSL VIII	Mezzanine	1,970		1,305		(665		)	C/C	29	59.12		0.00
Pre TSL IX	Mezzanine	2,340		1,442		(898		)	B3/C	39	28.91		6.73
Pre TSL X	Mezzanine	1,495		1,526		31			Caa1/C	44	31.03		0.00
Pre TSL XII	Mezzanine	5,523		3,361		(2,162		)	B3/C	66	26.96		0.00
Pre TSL XIII	Mezzanine	12,464		8,455		(4,009		)	Caa1/C	57	19.26		30.97
Pre TSL XIV	Mezzanine	13,035		8,081		(4,954		)	Caa1/C	56	24.54		36.53
MMCap I	Mezzanine	430		386		(44		)	Ca/C	11	59.52		20.89
Total		$	41,926	$	28,999	$	(12,927	)

Cumulative Roll Forward of Credit Losses Recognized in Earnings for Debt Securities Held and Not Intended to be Sold

The table below provides a cumulative roll forward of credit losses recognized in earnings for debt securities held and not intended to be sold for the years ended December 31:

	2014			2013			2012
	(dollars in thousands)
Balance, beginning (a)	$	27,543		$	43,274		$	44,736
Credit losses on debt securities for which other-than-temporary impairment was not previously recognized	—			—			—
Additional credit losses on debt securities for which other-than-temporary impairment was previously recognized	—			—			—
Increases in cash flows expected to be collected, recognized over the remaining life of the security (b)	(1,297		)	(2,375		)	(1,462		)
Reduction for debt securities called during the period	—			(13,356		)	—
Balance, ending	$	26,246		$	27,543		$	43,274

(a) The beginning balance represents credit related losses included in other-than-temporary impairment charges recognized on debt securities in prior periods.

(b) Represents the increase in cash flows recognized either as principal payments or interest income during the period.