BORROWINGS (SHUSA) (Details) (SHUSA [Member], USD $) Share data in Millions, unless otherwise specified			0 Months Ended							0 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Feb. 28, 2014 Trust PIERS [Member]	Jun. 30, 2014 3.00% senior notes, due September 2015 [Member]	Dec. 31, 2013 3.00% senior notes, due September 2015 [Member]	Jun. 30, 2014 4.625% senior notes, due April 2016 [Member]	Dec. 31, 2013 4.625% senior notes, due April 2016 [Member]	Jun. 30, 2014 3.45% senior notes, due August 2018 [Member]	Dec. 31, 2013 3.45% senior notes, due August 2018 [Member]	Feb. 21, 2014 Subordinated notes, due March 2020 [Member]	Jun. 30, 2014 Subordinated notes, due March 2020 [Member]		Dec. 31, 2013 Subordinated notes, due March 2020 [Member]		Jun. 30, 2014 Junior subordinate debentures - Capital Trust IV, due March 2034 [Member]		Dec. 31, 2013 Junior subordinate debentures - Capital Trust IV, due March 2034 [Member]		Jun. 30, 2014 Common securities - Capital Trust IV [Member]		Dec. 31, 2013 Common securities - Capital Trust IV [Member]		Jun. 30, 2014 Junior subordinate debentures - Capital Trust VI, due June 2036 [Member]	Dec. 31, 2013 Junior subordinate debentures - Capital Trust VI, due June 2036 [Member]	Jun. 30, 2014 Common securities - Capital Trust VI [Member]	Dec. 31, 2013 Common securities - Capital Trust VI [Member]	Jun. 30, 2014 Junior subordinate debentures - Capital Trust IX, due July 2036 [Member]	Dec. 31, 2013 Junior subordinate debentures - Capital Trust IX, due July 2036 [Member]	Jun. 30, 2014 Common securities - Capital Trust IX [Member]	Dec. 31, 2013 Common securities - Capital Trust IX [Member]
Debt Instrument [Line Items]
Senior notes, Balance				$ 599,258,000	$ 598,965,000	$ 474,666,000	$ 474,306,000	$ 499,232,000	$ 499,148,000
Subordinated notes, due March 2020, Balance											0	[1]	756,829,000	[1]
Subordinated debentures, Balance															0	[2]	611,000	[2]					70,262,000	70,262,000			150,000,000	150,000,000
Common securties, Balance																			0	[2]	24,742,000	[2]			10,000,000	10,000,000			4,640,000	4,640,000
Total holding company borrowings and other debt obligations	1,808,058,000	2,589,503,000
Effective Rate	3.88%	4.50%		3.28%	3.28%	4.85%	4.85%	3.62%	3.62%		0.00%	[1]	5.96%	[1]	0.00%	[2]	12.84%	[2]	0.00%	[2]	4.38%	[2]	7.91%	7.91%	7.91%	7.91%	2.02%	2.04%	2.02%	2.04%
Stated Rate				3.00%		4.625%		3.45%
Subordinated debt converted, original value										750,000,000
Number of shares issued upon conversion										3.0
Amount of securities called and retired			$ 24,700,000

[1] On February 21, 2014, the subordinated note, with a value of $750.0 million, was converted to 3.0 million shares of SHUSA common stock.

[2] In December 2012, a settlement agreement was executed with respect to the Company's Trust PIERS litigation. The settlement agreement required the Company to make additional offers to purchase the Trust PIERS until no Trust PIERS remain outstanding. On February 28, 2014, the Company called and retired the remaining PIERS securities in the amount of $24.7 million.