Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2012

Fair Value Measurements [Abstract]

Financial Assets And Financial Liabilities Measured At Fair Value On A Recurring Basis

	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
March 31, 2012
Securities available for sale:
U.S. Treasury	$	3,048,048	$	—	$	—	$	3,048,048
U.S. government agencies/corporations		—		250,782		—		250,782
Residential mortgage-backed securities		—		3,123,965		—		3,123,965
States and political subdivisions		—		2,107,411		—		2,107,411
Other		—		38,009		—		38,009
Trading account securities:
U.S. Treasury		13,409		—		—		13,409
States and political subdivisions		—		3,437		—		3,437
Derivative assets:
Interest rate swaps, caps and floors		—		56,523		610		57,133
Commodity and foreign exchange derivatives		—		17,734		—		17,734
Derivative liabilities:
Interest rate swaps, caps and floors		—		72,283		—		72,283
Commodity and foreign exchange derivatives		6		17,584		—		17,590
December 31, 2011
Securities available for sale:
U.S. Treasury	$	2,056,732	$	—	$	—	$	2,056,732
U.S. government agencies/corporations		—		250,884		—		250,884
Residential mortgage-backed securities		—		3,289,270		—		3,289,270
States and political subdivisions		—		2,154,813		—		2,154,813
Other		—		38,001		—		38,001
Trading account securities:
U.S. Treasury		13,609		—		—		13,609
Derivative assets:
Interest rate swaps, caps and floors		—		60,498		689		61,187
Commodity and foreign exchange derivatives		7		23,304		—		23,311
Derivative liabilities:
Interest rate swaps, caps and floors		—		77,626		—		77,626
Commodity and foreign exchange derivatives		—		23,139		—		23,139

Beginning And Ending Balances Of Derivative Assets Measured At Fair Value On A Recurring Basis

	Three Months Ended March 31,
	2012			2011
Balance, beginning of period	$	689		$	1,090
Cash settlements		(97	)		(112	)
Realized gains (losses) included in other non-interest income		(22	)		(35	)
Realized gains (losses) included in other non-interest expense		40			39
Balance, end of period	$	610		$	982

Impaired Loans Remeasured And Reported At Fair Value Of The Underlying Collateral

	Three Months Ended March 31, 2012					Three Months Ended March 31, 2011
	Level 2			Level 3		Level 2			Level 3
Carrying value of impaired loans before allocations	$	10,943		$	—	$	11,787		$	2,633
Specific valuation allowance allocations		(2,497	)		—		(3,205	)		(752	)
Fair value	$	8,446		$	—	$	8,582		$	1,881

Foreclosed Assets Remeasured And Reported At Fair Value

	Three Months Ended March 31,
	2012			2011
Foreclosed assets remeasured at initial recognition:
Carrying value of foreclosed assets prior to remeasurement	$	1,386		$	8,804
Charge-offs recognized in the allowance for loan losses		(315	)		(1,370	)
Fair value	$	1,071		$	7,434
Foreclosed assets remeasured subsequent to initial recognition:
Carrying value of foreclosed assets prior to remeasurement	$	372		$	936
Write-downs included in other non-interest expense		(75	)		(241	)
Fair value	$	297		$	695

Estimated Fair Values Of Financial Instruments

	March 31, 2012				December 31, 2011
	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Financial assets:
Level 2 inputs:
Cash and cash equivalents	$	2,128,734	$	2,128,734	$	2,907,592	$	2,907,592
Securities held to maturity		365,603		402,829		365,996		404,461
Cash surrender value of life insurance policies		135,035		135,035		133,967		133,967
Accrued interest receivable		61,833		61,833		78,869		78,869
Level 3 inputs:
Loans, net		8,019,532		8,119,248		7,884,982		7,951,742
Financial liabilities:
Level 2 inputs:
Deposits		16,909,021		16,909,615		16,756,748		16,757,708
Federal funds purchased and repurchase agreements		637,098		637,098		722,202		722,202
Junior subordinated deferrable interest debentures		123,712		123,712		123,712		123,712
Subordinated notes payable and other borrowings		100,022		86,094		100,026		100,101
Accrued interest payable		2,212		2,212		4,431		4,431