MORTGAGE SERVICING RIGHTS (Details) (USD $)	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Activity related to capitalized MSRs
Beginning balance	$ 315,524,000	$ 137,079,000
Additions, following the sale of loan	38,793,000	13,027,000
Amortization	(15,105,000)	(6,350,000)
Pre-payments and write-offs	(2,815,000)	(1,135,000)
Ending balance	336,397,000	142,621,000
Fair value of the MSRs	373,700,000		350,500,000
Decrease in fair value as a result of 100 basis point increase in discount rate	11,700,000
Decrease in fair value as a result of 200 basis point increase in discount rate	$ 22,700,000
Sensitivity Analysis of Fair Value, example 1, impact of percent adverse change in discount rate, percent	0.01
Sensitivity Analysis of Fair Value, example 2, impact of percent adverse change in discount rate, percent	0.02
Minimum
Discount rate
Discount rate used for loans originated (as a percent)	10.00%	10.00%
Reduction in estimated life	6 months
Maximum
Discount rate
Discount rate used for loans originated (as a percent)	15.00%	15.00%
Reduction in estimated life	12 months

Amortized carrying amount (balance) as of the balance sheet date of an asset representing net future revenues from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

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The value of new servicing assets, subsequently measured at amortized value, acquired or created during the current period through purchases or from transfers of financial assets.

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Amount of expense charged against earnings for the periodic recognition of servicing assets relative to estimated net servicing income.

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Fair value as of the balance sheet date of an asset representing net future revenues from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

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The discount rate used to estimate the fair value of servicing assets and servicing liabilities.

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The hypothetical financial impact of a 1 percent adverse change in the discount rate on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

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The hypothetical financial impact of a 2 percent adverse change in the discount rate on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

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A specified percentage variance in the discount rate assumption in the determination of fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date, sensitivity scenario 1.

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Decreases in the carrying value of servicing assets measured using the amortization method related to pre-payments and write-offs.

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Represents the reduction in estimated life of financial assets and financial liabilities based upon the expiration of various types of prepayment penalty and/or lockout provisions prior to that stated maturity date.

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