LOANS AND ALLOWANCE FOR CREDIT LOSSES (Loan and Lease Portfolio Composition) (Details) (USD $)	Jun. 30, 2014		Dec. 31, 2013
Loans Receivable [Line Items]
Loans held for investment	$ 75,637,888,000	[1],[2]	$ 49,921,677,000	[1],[2]
Loans held for investment with fixed rate of interest	47,478,105,000		23,431,663,000
Loans held for investment with variable rate of interest	28,159,783,000		26,490,014,000
Loans held for investment, percent of total loans	100.00%	[2]	100.00%	[2]
Loans held for investment with fixed rate of interest, percent of total loans	62.80%		46.90%
Loans held for investment with variable rate of interest, percent of total loans	37.20%		53.10%
Loans held for investment, deferred income	(2,200,000,000)		122,600,000
Commercial [Member]
Loans Receivable [Line Items]
Loans held for investment	35,001,993,000		32,151,222,000
Loans held for investment, percent of total loans	46.20%		64.40%
Commercial [Member] | Commercial real estate loans [Member]
Loans Receivable [Line Items]
Loans held for investment	8,897,785,000		9,303,885,000
Loans held for investment, percent of total loans	11.80%		18.60%
Commercial [Member] | Commercial and industrial loans [Member]
Loans Receivable [Line Items]
Loans held for investment	14,954,380,000		12,820,417,000
Loans held for investment, percent of total loans	19.80%		25.70%
Commercial [Member] | Multi-family loans [Member]
Loans Receivable [Line Items]
Loans held for investment	9,229,611,000		8,237,029,000
Loans held for investment, percent of total loans	12.20%		16.50%
Commercial [Member] | Other commercial [Member]
Loans Receivable [Line Items]
Loans held for investment	1,920,217,000	[3]	1,789,891,000	[3]
Loans held for investment, percent of total loans	2.40%	[3]	3.60%	[3]
Consumer [Member]
Loans Receivable [Line Items]
Loans held for investment	40,635,895,000		17,770,455,000
Loans held for investment, percent of total loans	53.80%		35.60%
Consumer loans secured by real estate [Member]
Loans Receivable [Line Items]
Loans held for investment	15,693,498,000		15,872,881,000
Loans held for investment, percent of total loans	20.80%		31.80%
Consumer loans secured by real estate [Member] | Residential mortgages [Member]
Loans Receivable [Line Items]
Loans held for investment	9,503,023,000	[4]	9,561,187,000	[4]
Loans held for investment, percent of total loans	12.60%		19.20%
Consumer loans secured by real estate [Member] | Home equity loans and lines of credit [Member]
Loans Receivable [Line Items]
Loans held for investment	6,190,475,000		6,311,694,000
Loans held for investment, percent of total loans	8.20%		12.60%
Consumer loans not secured by real estate [Member] | Retail installment contracts and auto loans [Member]
Loans Receivable [Line Items]
Loans held for investment	21,623,534,000	[5]	81,804,000	[5]
Loans held for investment, percent of total loans	28.60%		0.20%
Consumer loans not secured by real estate [Member] | Personal unsecured loan [Member]
Loans Receivable [Line Items]
Loans held for investment	1,861,805,000		493,785,000
Loans held for investment, percent of total loans	2.50%		1.00%
Consumer loans not secured by real estate [Member] | Other consumer [Member]
Loans Receivable [Line Items]
Loans held for investment	$ 1,457,058,000	[6]	$ 1,321,985,000	[6]
Loans held for investment, percent of total loans	1.90%	[6]	2.60%	[6]

[1] Loans held for investment includes $1.3 billion and $0.0 billion of loans recorded at fair value at June 30, 2014 and December 31, 2013, respectively.

[2] Total loans held for investment includes deferred loan fees, net of deferred origination costs and unamortized purchase premiums, net of discounts as well as purchase accounting adjustments. These items resulted in a net decrease in loan balances of $2.2 billion as of June 30, 2014 and a net increase in loan balances of $122.6 million as of December 31, 2013, respectively. The significant fluctuation between periods is due to the purchase accounting marks resulting from the Change in Control of SCUSA.

[3] Other commercial primarily includes commercial equipment vehicle funding ("CEVF") and loans.

[4] Home mortgages excludes $148.7 million and $111.0 million of LHFS at June 30, 2014 and December 31, 2013, respectively.

[5] Retail installment contracts and auto loans excludes $89.4 million and $0.0 million of LHFS at June 30, 2014 and December 31, 2013, respectively.

[6] Other consumer primarily includes recreational vehicles and marine loans.