Investment Securities (Tables)

6 Months Ended

Jun. 30, 2011

Investments Securities [Abstract]

Amortized cost and fair value for the major categories of held-to-maturity and available-for-sale securities

	June 30, 2011
			Gross		Gross
	Amortized		Unrealized		Unrealized			Fair
	Cost		Gains		Losses			Value
Securities available for sale
Debt Securities
U.S. government agency debentures		370,649		743		(148	)		371,244
U.S. States and political subdivisions		299,238		10,728		(181	)		309,785
Residential mortgage-backed securities:
U.S. government agencies		1,528,537		60,524		(90	)		1,588,971
Residential collateralized mortgage-backed securities:
U.S. government agencies		1,061,393		19,883		(1,326	)		1,079,950
Non-agency		93,733		114		—			93,847
Corporate debt securities		61,461		—		(10,738	)		50,723
Total debt securities		3,415,011		91,992		(12,483	)		3,494,520
Marketable equity securities		3,752		—		—			3,752
Total securities available for sale	$	3,418,763	$	91,992	$	(12,483	)	$	3,498,272
Securities held to maturity
Debt Securities
U.S. States and political subdivisions	$	80,857	$	—	$	—		$	80,857
Total securities held to maturity	$	80,857	$	—	$	—		$	80,857

	December 31, 2010
	Amortized		Gross Unrealized		Gross Unrealized			Fair
	Cost		Gains		Losses			Value
Securities available for sale
Debt Securities
U.S. government agency debentures	$	399,122	$	703	$	(194	)	$	399,631
U.S. States and political subdivisions		296,327		3,537		(2,119	)		297,745
Residential mortgage-backed securities:
U.S. government agencies		1,343,021		52,230		(547	)		1,394,704
Residential collateralized mortgage-backed securities:
U.S. government agencies		814,774		18,223		(2,306	)		830,691
Non-agency		15,018		—		—			15,018
Corporate debt securities		61,435		—		(16,106	)		45,329
Total debt securities		2,929,697		74,693		(21,272	)		2,983,118
Marketable equity securities		3,922		—		—			3,922
Total securities available for sale	$	2,933,619	$	74,693	$	(21,272	)	$	2,987,040
Securities held to maturity
Debt Securities
U.S. States and political subdivisions	$	59,962	$	—	$	—		$	59,962
Total securities held to maturity	$	59,962	$	—	$	—		$	59,962

	June 30, 2010
	Amortized		Gross Unrealized		Gross Unrealized			Fair
	Cost		Gains		Losses			Value
Securities available for sale
Debt Securities
U.S. Treasury	$	50,000	$	—	$	—		$	50,000
U.S. government agency debentures		326,338		1,130		(21	)		327,447
U.S. States and political subdivisions		286,297		7,960		(81	)		294,176
Residential mortgage-backed securities:
U.S. government agencies		1,491,498		72,850		(63	)		1,564,285
Residential collateralized mortgage-backed securities:
U.S. government agencies		761,197		23,543		—			784,740
Non-agency		20		—		(1	)		19
Corporate debt securities		61,410		—		(17,968	)		43,442
Total debt securities		2,976,760		105,483		(18,134	)		3,064,109
Marketable equity securities		3,443		—		—			3,443
Total securities available for sale	$	2,980,203	$	105,483	$	(18,134	)	$	3,067,552
Securities held to maturity
Debt Securities
U.S. States and political subdivisions	$	65,160	$	—	$	—		$	65,160
Total securities held to maturity	$	65,160	$	—	$	—		$	65,160

Other investments

          Federal Reserve Bank (“FRB”) and Federal Home Loan Bank (“FHLB”) stock constitute the majority of other investments on the consolidated balance sheet.

	June 30,		December 31,		June 30,
	2011		2010		2010
FRB stock	$	20,804	$	20,725	$	19,787
FHLB stock		139,398		139,398		139,398
Other		603		629		1,037
Total other investments	$	160,805	$	160,752	$	160,222

Gross unrealized losses and fair value of securities

Gross Unrealized Losses and Fair Value

          The following table presents the gross unrealized losses and fair value of securities in the securities available-for-sale portfolio by length of time that individual securities in each category had been in a continuous loss position.

	June 30, 2011
	Less than 12 months							12 months or longer							Total
						Number of							Number of
						Impaired							Impaired
	Fair Value		Unrealized Losses			Securities		Fair Value		Unrealized Losses			Securities		Fair Value		Unrealized Losses
Debt Securities
U.S. government agency debentures	$	23,538	$	(148	)		2	$	—	$	—			—	$	23,538	$	(148	)
U.S. States and political subdivisions		18,176		(158	)		24		655		(23	)		1		18,831		(181	)
Residential mortgage-backed securities:
U.S. government agencies		14,229		(87	)		1		182		(3	)		2		14,411		(90	)
Residential collateralized mortgage-backed securities:
U.S. government agencies		265,319		(1,326	)		18		—		—			—		265,319		(1,326	)
Corporate debt securities		—		—			—		50,723		(10,738	)		8		50,723		(10,738	)
Total temporarily impaired securities	$	321,262	$	(1,719	)		45	$	51,560	$	(10,764	)		11	$	372,822	$	(12,483	)

	December 31, 2010
	Less than 12 months							12 months or longer							Total
						Number of							Number of
						Impaired							Impaired
	Fair Value		Unrealized Losses			Securities		Fair Value		Unrealized Losses			Securities		Fair Value		Unrealized Losses
Debt Securities
U.S. government agency debentures	$	109,238	$	(194	)		8	$	—	$	—			—	$	109,238	$	(194	)
U.S. States and political subdivisions		105,530		(2,095	)		164		665		(24	)		1		106,195		(2,119	)
Residential mortgage-backed securities:
U.S. government agencies		67,474		(544	)		7		195		(3	)		1		67,669		(547	)
Residential collateralized mortgage-backed securities:
U.S. government agencies		188,264		(2,306	)		17		—		—			—		188,264		(2,306	)
Non-agency		—		—			—		—		—			—		—		—
Corporate debt securities		—		—			—		45,329		(16,106	)		8		45,329		(16,106	)
Total temporarily impaired securities	$	470,506	$	(5,139	)		196	$	46,189	$	(16,133	)		10	$	516,695	$	(21,272	)

	June 30, 2010
	Less than 12 months							12 months or longer							Total
						Number of							Number of
						Impaired							Impaired
	Fair Value		Unrealized Losses			Securities		Fair Value		Unrealized Losses			Securities		Fair Value		Unrealized Losses
Debt Securities
U.S. government agency debentures	$	30,275	$	(21	)		2	$	—	$	—			—	$	30,275	$	(21	)
U.S. States and political subdivisions		13,822		(68	)		20		689		(13	)		1		14,511		(81	)
Residential mortgage-backed securities:
U.S. government agencies		15,016		(60	)		2		227		(3	)		1		15,243		(63	)
Residential collateralized mortgage-backed securities:
Non-agency		3		(1	)		1		—		—			—		3		(1	)
Corporate debt securities		—		—			—		43,442		(17,968	)		8		43,442		(17,968	)
Total temporarily impaired securities	$	59,116	$	(150	)		25	$	44,358	$	(17,984	)		10	$	103,474	$	(18,134	)

Proceeds and gross unrealized gains and losses on sales of available-for-sale securities

Realized Gains and Losses

          The following table shows the proceeds from sales of available-for-sale- securities and the gross unrealized gains and losses on the sales of those securities that have been included in earnings as a result of those sales. Gains or losses on the sales of available-for-sale securities are recognized upon sale and are determined using the specific identification method.

	Quarter ended						Six months ended
	June 30,						June 30,
	2011			2010			2011			2010
Proceeds	$	32,900		$	487,905		$	32,900		$	500,006
Realized gains	$	945		$	1,602		$	945		$	1,602
Realized losses		(56	)		(951	)		(56	)		(951	)
Net securities gains	$	889		$	651		$	889		$	651

Contractual maturities and contractual yields of debt securities held-to-maturity and available-for-sale

										Residential			Residential
							Residential			collateralized			collateralized
				U.S. States and			mortgage-backed			mortgage			mortgage
	U.S. Government			political			securities - U.S			obligations - U.S.			obligations - non -
	agency			subdivisions			govt. agency			govt. agency			U.S. govt. agency			Corporate debt						Weighted
	debentures			obligations			obligations			obligations			issued			securities			Total			Average Yield
Securities Available for Sale
Remaining maturity:
One year or less	$	259,805		$	10,313		$	4,067		$	34,945		$	—		$	—		$	309,130			1.35	%
Over one year through five years		111,439			21,351			1,479,708			1,045,005			17,643			—			2,675,146			2.92	%
Over five years through ten years		—			137,952			105,196			—			76,204			—			319,352			3.34	%
Over ten years		—			140,169			—			—			—			50,723			190,892			4.55	%
Fair Value	$	371,244		$	309,785		$	1,588,971		$	1,079,950		$	93,847		$	50,723		$	3,494,520			2.92	%
Amortized Cost	$	370,649		$	299,238		$	1,528,537		$	1,061,393		$	93,733		$	61,461		$	3,415,011
Weighted-Average Yield		0.74	%		5.69	%		3.45	%		2.43	%		0.62	%		0.99	%		2.92	%
Weighted-Average Maturity		0.7			9.1			3.3			2.8			5.9			16.3			3.7
Securities Held to Maturity
Remaining maturity:
One year or less	$	—		$	27,770		$	—		$	—		$	—		$	—		$	27,770			3.79	%
Over one year through five years		—			14,507			—			—			—			—			14,507			3.79	%
Over five years through ten years		—			3,780			—			—			—			—			3,780			3.79	%
Over ten years		—			34,800			—			—			—			—			34,800			7.29	%
Fair Value	$	—		$	80,857		$	—		$	—		$	—		$	—		$	80,857			5.30	%
Amortized Cost	$	—		$	80,857		$	—		$	—		$	—		$	—		$	80,857
Weighted-Average Yield					5.30	%														5.30	%
Weighted-Average Maturity					7.4															7.4