Investment Securities (Tables)

12 Months Ended

Dec. 31, 2011

Investment Securities [Abstract]

Amortized Cost and Estimated Fair Value of Investment Securities

	December 31, 2011
	Amortized Cost		Gross Unrealized Holding Gain		Gross Unrealized Holding Loss			Fair Value		Total Percent
			(Dollars in thousands)
Investment Securities Available-for-Sale:
Government agency & government-sponsored enterprises	$	46,273	$	234	$	—		$	46,507		2.11	%
Residential mortgage-backed securities		869,847		18,487		(334	)		888,000		40.33	%
CMO’s / REMIC’s–Residential		594,866		10,307		(665	)		604,508		27.46	%
Municipal bonds		608,575		43,665		(203	)		652,037		29.62	%
Other securities		10,468		10		(4	)		10,474		0.48	%
Total Investment Securities	$	2,130,029	$	72,703	$	(1,206	)	$	2,201,526		100.00	%

	December 31, 2010
	Amortized Cost		Gross Unrealized Holding Gain		Gross Unrealized Holding Loss			Fair Value		Total Percent
	(Dollars in thousands)
Investment Securities Available-for-Sale:
Government agency & government-sponsored enterprises	$	106,368	$	119	$	(214	)	$	106,273		5.93	%
Residential mortgage-backed securities		801,370		13,405		(6,366	)		808,409		45.12	%
CMO’s / REMIC’s–Residential		267,556		4,300		(1,379	)		270,477		15.10	%
Municipal bonds		605,199		10,943		(9,743	)		606,399		33.85	%
Total Investment Securities	$	1,780,493	$	28,767	$	(17,702	)	$	1,791,558		100.00	%

Summary of Continuous Loss Position of Securities

	December 31, 2011
	Less than 12 months				12 months or longer				Total
Description of Securities	Fair Value		Gross Unrealized Holding Losses		Fair Value		Gross Unrealized Holding Losses		Fair Value		Gross Unrealized Holding Losses
	(Dollars in thousands)
Held-To-Maturity
CMO	$	2,383	$	—	$	—	$	—	$	2,383	$	—
Available-for-Sale
Government agency	$	—	$	—	$	—	$	—	$	—	$	—
Residential mortgage-backed securities		75,754		334		—		—		75,754		334
CMO/REMICs—Residential		133,471		665		—		—		133,471		665
Municipal bonds		22,184		203		—		—		22,184		203
Other Securities		2,500		4		—		—		2,500		4
	$	233,909	$	1,206	$	—	$	—	$	233,909	$	1,206
	December 31, 2010
	Less than 12 months				12 months or longer				Total
Description of Securities	Fair Value		Gross Unrealized Holding Losses		Fair Value		Gross Unrealized Holding Losses		Fair Value		Gross Unrealized Holding Losses
	(Dollars in thousands)
Held-To-Maturity
CMO	$	—	$	—	$	3,143	$	401	$	3,143	$	401
Available-for-Sale
Government agency	$	79,635	$	214	$	—	$	—	$	79,635	$	214
Residential mortgage-backed securities		449,806		6,366		—		—		449,806		6,366
CMO/REMICs—Residential		144,234		1,379		—		—		144,234		1,379
Municipal bonds		225,928		8,844		5,585		899		231,513		9,743
	$	899,603	$	16,803	$	5,585	$	899	$	905,188	$	17,702

Roll-Forward of Credit-Related Other-Than-Temporary Impairment Recognized in Earnings

	For the Year Ended December 31, 2011
	(Dollars in thousands)
Balance, beginning of the period	$	1,227
Addition of OTTI that was not previously recognized		656
Reduction for securities sold during the period		—
Reduction for securities with OTTI recognized in earnings because the security might be sold before recovery of its amortized cost basis that are recognized over the remaining life of the security		—
Balance, end of the period	$	1,883

Amortized Cost and Fair Value of Debt Securities by Contractual Maturity

	Available-for-sale
	Amortized Cost		Fair Value		Weighted- Average Yield
	(Dollars in thousands)
Due in one year or less	$	124,996	$	127,168		3.22	%
Due after one year through five years		1,630,781		1,679,549		2.81	%
Due after five years through ten years		321,947		340,109		3.70	%
Due after ten years		52,305		54,700		3.65	%
	$	2,130,029	$	2,201,526		2.99	%