Represents the amount of loans in the portfolio that are guaranteed by US government and were previously sold into GNMA mortgage pool and subsequently repurchased by company.

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Describes the general components and status of home equity loans serviced by the entity outstanding as of the Balance Sheet date.

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The generally accepted maximum balance outstanding at any month end during the period as of the Balance Sheet date for Home Equity Loans issued by the entity .

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Reflects the aggregate gross carrying amount of all loans in portfolio to businesses and individuals in the state of Oklahoma.

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Reflects the aggregate gross carrying amount of all loans in portfolio to businesses and individuals in the state of Texas.

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Reflects the aggregate gross carrying amount of all loans in portfolio to businesses in the state of Oklahoma.

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Reflects the aggregate gross carrying amount of all loans in portfolio to businesses in the state of Texas.

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Reflects the percentage of the total loan portfolio to businesses and individuals in the state of Oklahoma.

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Reflects the percentage of the total loan portfolio to businesses and individuals in the state of Texas.

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Reflects the percentage of the total loan portfolio to businesses in the state of Oklahoma.

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Reflects the percentage of the total loan portfolio to businesses in the state of Texas.

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Maximum dollar amount of loans in this category with individual loan amount less than specified threshold.

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Represents the maximum debt-to-income (DTI) ratio on loans approved.

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Maximum loan amount for specified individual loans in category.

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Represents the minimum FICO score required for loan approval.

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Represents the minimum loan-to-value (LTV) ratio acceptable for loans to be approved.

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Outstanding commitments to extend credit based on existing credit policies.

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An irrevocable guarantee to extend credit to a party based on current credit policies.

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Reflects the percentage of the loan in portfolio secured by property in the state of Oklahoma.

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Reflects the percentage of the loan in portfolio secured by property in the state of Texas.

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The maximum number of years that variable rate jumbo loans will have their interest rate fixed.

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The minimum number of years that variable rate jumbo loans will have their interest rate fixed.

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Represents the maximum loan-to-value (LTV) ratio on loans approved.

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Recorded investment in financing receivables that are 90 days or more past due and still accruing.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Reflects the aggregate gross carrying amount of all categories of loans and leases held in portfolio, prior to deducting deferred income and the allowance for losses on loans and leases.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

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Reflects the carrying amount of loans deemed to be questionable as to collection on which no interest is continuing to be recognized.

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-Publisher AICPA

-Name Statement of Position (SOP)

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Reflects the carrying amount of loans charging borrowers fixed rates of interest.

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Reflects the carrying amount of loans charging borrowers variable, or adjustable, rates of interest.

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Loans Part 1 (Details) (USD $)	9 Months Ended
Loans Part 1 (Details) (USD $)	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010	Sep. 30, 2011 Commercial Portfolio Segment [Member]	Jun. 30, 2011 Commercial Portfolio Segment [Member]	Dec. 31, 2010 Commercial Portfolio Segment [Member]	Sep. 30, 2011 Commercial Portfolio Segment [Member] Commercial Services Financing Receivable [Member]	Sep. 30, 2011 Commercial Real Estate Portfolio Segment [Member]	Jun. 30, 2011 Commercial Real Estate Portfolio Segment [Member]	Dec. 31, 2010 Commercial Real Estate Portfolio Segment [Member]	Sep. 30, 2011 Residential Portfolio Segment [Member]	Jun. 30, 2011 Residential Portfolio Segment [Member]	Dec. 31, 2010 Residential Portfolio Segment [Member]	Jun. 30, 2011 Consumer Portfolio Segment [Member]	Dec. 31, 2010 Consumer Portfolio Segment [Member]
Loan receivables disclosure [Abstract]
Loans receivables with fixed rate of interest	$ 5,139,107,000	$ 4,934,153,000			$ 3,054,787,000	$ 2,883,905,000			$ 864,053,000	$ 829,836,000		$ 954,960,000	$ 851,048,000	$ 265,307,000	$ 369,364,000
Loans receivables with variable rate of interest	5,755,987,000	5,478,069,000			3,337,166,000	3,011,636,000			1,285,801,000	1,297,148,000		925,205,000	939,774,000	207,815,000	229,511,000
Loan receivable non-accrual	229,475,000	230,814,000			83,736,000	38,455,000			110,048,000	150,366,000		31,731,000	37,426,000	3,960,000	4,567,000
Total	11,124,569,000	10,643,036,000	10,805,844,000		6,475,689,000	5,933,996,000			2,259,902,000	2,277,350,000		1,911,896,000	1,828,248,000	477,082,000	603,442,000
Accruing loans past due (90 days)	1,401,000	7,966,000
Loans receivable, other information [Abstract]
Amount of total loan portfolio to businesses and individuals in Oklahoma	5,000,000,000
Percentage of total loan portfolio to businesses and individuals in Oklahoma (in hundredths)	45.00%
Amount of total loan portfolio to businesses and individuals in Texas	3,200,000,000
Percentage of total loan portfolio to businesses and individuals in Texas (in hundredths)	29.00%
Amount Of loans with individual balances less than $10 million							1,000,000,000
Maximum loan amount for certain individual loans in category							10,000,000
Amount of loan portfolio to businesses in Oklahoma				2,800,000,000
Percentage of loan portfolio to businesses in Oklahoma (in hundredths)				43.00%
Amount of loan portfolio to businesses in Texas				2,100,000,000
Percentage of loan portfolio to businesses in Texas (in hundredths)								32.00%
Percentage of loan portfolio secured by property in Texas (in hundredths)				33.00%
Percentage of loan portfolio secured by property in Oklahoma (in hundredths)								28.00%
Minimum FICO required for jumbo loan approval											720
Maximum debt-to-income ratio on jumbo loans (in hundredths)											38.00%
Minimum loan-to-value ratio on jumbo loans (in hundredths)											60.00%
Maximum loan-to-value ratio on jumbo loans (in hundredths)											100.00%
Minimum period for fixed rate on variable rate jumbo loans (in years)											3 Y
Maximum period for fixed rate on variable rate jumbo loans (in years)											10 Y
Amount of loans guaranteed by US government and previously sold into GNMA mortgage pools											169,000,000		48,000,000
Home equity loans, description	Home equity loans are generally first or second lien loans with a maximum LTV of 100, including consideration of any superior liens. The loans require a minimum FICO score of 700 and a maximum DTI of 40.
Home equity loans, maximum	400,000
Credit Commitments [Abstract]
Outstanding commitments to extend credit	5,700,000,000
Outstanding standby letters of credit	509,000,000
Outstanding commercial letters of credit	$ 7,000,000