BUSINESS SEGMENT INFORMATION (Segment Reporting Information) (Details) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Segment Reporting Information [Line Items]
Net interest income	$ 1,590,034,000		$ 385,277,000		$ 2,762,139,000		$ 781,295,000
Total non-interest income	638,290,000		254,392,000		3,499,546,000		674,213,000
Total non-interest income					1,071,007,000
Gain on change in control	0		0		2,428,539,000	[1]	0
Provision for credit losses	686,034,000		10,000,000		1,021,364,000		26,850,000
Total expenses	1,003,229,000		406,434,000		1,773,610,000		817,254,000
Income/(loss) before income taxes	539,061,000		223,235,000		3,466,711,000		611,404,000
Intersegment (expense)/revenue	0	[2]	0	[2]	0	[2]	0	[2]
Total average assets	109,090,141,000		80,542,768,000		102,947,979,000		82,447,787,000
SCUSA [Member]
Segment Reporting Information [Line Items]
Net interest income	1,083,651,000	[1],[3]	0		2,145,853,000	[3]	0
Total non-interest income			116,909,000				305,430,000
Total non-interest income	314,172,000	[1],[3]			553,770,000	[3]
Gain on change in control					0	[1],[3]
Provision for credit losses	588,577,000	[1],[3]	0		1,287,155,000	[3]	0
Total expenses	419,121,000	[1],[3]	0		892,837,000	[3]	0
Income/(loss) before income taxes	390,125,000	[1],[3]	116,909,000		519,631,000	[3]	305,430,000
Intersegment (expense)/revenue	0	[1],[2],[3]	0	[2]	0	[2],[3]	0	[2]
Total average assets	29,409,369,000	[1],[3]	0		23,864,215,000	[3]	0
Purchase Price Adjustments [Member] | SCUSA [Member]
Segment Reporting Information [Line Items]
Net interest income	108,967,000	[3]			179,957,000	[3]
Total non-interest income	161,914,000	[3]			245,142,000	[3]
Gain on change in control					2,428,539,000	[1],[3]
Provision for credit losses	137,457,000	[3]			(337,000)	[3]
Total expenses	14,603,000	[3]			105,153,000	[3]
Income/(loss) before income taxes	118,821,000	[3]			2,748,822,000	[3]
Intersegment (expense)/revenue	0	[2],[3]			0	[2],[3]
Total average assets	0	[3]			0	[3]
Eliminations [Member]
Segment Reporting Information [Line Items]
Net interest income	0	[3]			(344,136,000)	[3]
Total non-interest income	(23,977,000)	[3]			(83,980,000)	[3]
Gain on change in control					0	[1],[3]
Provision for credit losses	0	[3]			(225,454,000)	[3]
Total expenses	(7,418,000)	[3]			(253,083,000)	[3]
Income/(loss) before income taxes	(16,559,000)	[3]			50,421,000	[3]
Intersegment (expense)/revenue	0	[2],[3]			0	[2],[3]
Total average assets	0	[3]			0	[3]
Retail Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	214,495,000		181,908,000		429,586,000		366,197,000
Total non-interest income			112,856,000				220,456,000
Total non-interest income	83,428,000				170,846,000
Gain on change in control					0	[1]
Provision for credit losses	11,134,000		15,015,000		20,344,000		62,711,000
Total expenses	253,041,000		214,989,000		499,882,000		436,461,000
Income/(loss) before income taxes	33,748,000		64,760,000		80,206,000		87,481,000
Intersegment (expense)/revenue	61,617,000	[2]	21,550,000	[2]	126,253,000	[2]	39,462,000	[2]
Total average assets	18,695,696,000		19,645,132,000		18,746,035,000		20,130,286,000
Auto Finance & Alliances [Member]
Segment Reporting Information [Line Items]
Net interest income	18,696,000		15,209,000		37,543,000		30,144,000
Total non-interest income			483,000				942,000
Total non-interest income	34,312,000				40,372,000
Gain on change in control					0	[1]
Provision for credit losses	1,694,000		2,480,000		1,690,000		2,324,000
Total expenses	35,620,000		1,876,000		46,037,000		4,060,000
Income/(loss) before income taxes	15,694,000		11,336,000		30,188,000		24,702,000
Intersegment (expense)/revenue	(3,248,000)	[2]	(2,714,000)	[2]	(5,418,000)	[2]	(5,621,000)	[2]
Total average assets	2,925,777,000		1,755,659,000		2,638,505,000		1,749,950,000
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	129,579,000		111,358,000		247,613,000		219,964,000
Total non-interest income			37,136,000				64,959,000
Total non-interest income	23,365,000				49,279,000
Gain on change in control					0	[1]
Provision for credit losses	(12,019,000)		9,490,000		(7,352,000)		(6,555,000)
Total expenses	44,603,000		42,016,000		89,857,000		83,084,000
Income/(loss) before income taxes	120,360,000		96,988,000		214,387,000		208,394,000
Intersegment (expense)/revenue	(76,817,000)	[2]	(95,912,000)	[2]	(161,208,000)	[2]	(191,837,000)	[2]
Total average assets	22,780,861,000		21,665,719,000		22,579,026,000		21,611,348,000
Global Banking & Markets [Member]
Segment Reporting Information [Line Items]
Minimum annual revenue to service corporations	500,000,000				500,000,000
Net interest income	45,460,000		44,328,000		87,015,000		85,049,000
Total non-interest income			21,444,000				46,748,000
Total non-interest income	15,194,000				37,621,000
Gain on change in control					0	[1]
Provision for credit losses	(4,199,000)		2,015,000		(1,761,000)		7,492,000
Total expenses	19,447,000		13,359,000		35,637,000		25,963,000
Income/(loss) before income taxes	45,406,000		50,398,000		90,760,000		98,342,000
Intersegment (expense)/revenue	(9,020,000)	[2]	(12,553,000)	[2]	(18,096,000)	[2]	(25,213,000)	[2]
Total average assets	9,213,611,000		8,295,728,000		8,828,262,000		8,407,450,000
Global Banking & Markets [Member] | SCUSA [Member]
Segment Reporting Information [Line Items]
Equity method investment, ownership percentage			65.00%				65.00%
Global Banking & Markets [Member] | SCUSA [Member]
Segment Reporting Information [Line Items]
Noncontrolling interest, ownership percentage by parent	39.00%				39.00%
Other [Member]
Segment Reporting Information [Line Items]
Net interest income	(10,814,000)	[4]	32,474,000	[4]	(21,292,000)	[4]	79,941,000	[4]
Total non-interest income			(34,436,000)	[4]			35,678,000	[4]
Total non-interest income	29,882,000	[4]			57,957,000	[4]
Gain on change in control					0	[1],[4]
Provision for credit losses	(36,610,000)	[4]	(19,000,000)	[4]	(52,921,000)	[4]	(39,122,000)	[4]
Total expenses	224,212,000	[4]	134,194,000	[4]	357,290,000	[4]	267,686,000	[4]
Income/(loss) before income taxes	(168,534,000)	[4]	(117,156,000)	[4]	(267,704,000)	[4]	(112,945,000)	[4]
Intersegment (expense)/revenue	27,468,000	[2],[4]	89,629,000	[2],[4]	58,469,000	[2],[4]	183,209,000	[2],[4]
Total average assets	$ 26,064,827,000	[4]	$ 29,180,530,000	[4]	$ 26,291,936,000	[4]	$ 30,548,753,000	[4]

[1] Management of SHUSA manages SCUSA by analyzing the pre-Change in Control results of SCUSA as disclosed in this column.

[2] Intersegment revenue/(expense) represents charges or credits for funds used or provided by each of the segments and is included in net interest income.

[3] Purchase Price Adjustments represents the impact that SCUSA purchase marks had on the results of SCUSA included within the consolidated operations of SHUSA, while eliminations adjust for the one month that SHUSA accounted for SCUSA as an equity method investment and eliminate intercompany transactions.

[4] Other is not considered a segment and includes earnings from non-strategic assets, the investment portfolio, interest expense on the Bank’s borrowings and other debt obligations, amortization of intangible assets and certain unallocated corporate income and indirect expenses.