BORROWINGS (SHUSA) (Details) (SHUSA [Member], USD $) Share data in Millions, unless otherwise specified	0 Months Ended
	Feb. 28, 2014	Feb. 21, 2014	Sep. 30, 2014		Dec. 31, 2013
Debt Instrument [Line Items]
Total holding company borrowings and other debt obligations			$ 1,808,432,000		$ 2,589,503,000
Effective Rate			3.88%		4.50%
Trust PIERS [Member]
Debt Instrument [Line Items]
Amount of securities called and retired	24,700,000
3.00% senior notes, due September 2015 [Member]
Debt Instrument [Line Items]
Senior notes, Balance			599,406,000		598,965,000
Effective Rate			3.28%		3.28%
Stated Rate			3.00%
4.625% senior notes, due April 2016 [Member]
Debt Instrument [Line Items]
Senior notes, Balance			474,849,000		474,306,000
Effective Rate			4.85%		4.85%
Stated Rate			4.625%
3.45% senior notes, due August 2018 [Member]
Debt Instrument [Line Items]
Senior notes, Balance			499,275,000		499,148,000
Effective Rate			3.62%		3.62%
Stated Rate			3.45%
Subordinated notes, due March 2020 [Member]
Debt Instrument [Line Items]
Subordinated notes, due March 2020, Balance			0	[1]	756,829,000	[1]
Effective Rate			0.00%	[1]	5.96%	[1]
Subordinated debt converted, original value		750,000,000
Number of shares issued upon conversion		3.0
Junior subordinate debentures - Capital Trust IV, due March 2034 [Member]
Debt Instrument [Line Items]
Subordinated debentures, Balance			0	[2]	611,000	[2]
Effective Rate			0.00%	[2]	12.84%	[2]
Common securities - Capital Trust IV [Member]
Debt Instrument [Line Items]
Common securties, Balance			0	[2]	24,742,000	[2]
Effective Rate			0.00%	[2]	4.38%	[2]
Junior subordinate debentures - Capital Trust VI, due June 2036 [Member]
Debt Instrument [Line Items]
Subordinated debentures, Balance			70,262,000		70,262,000
Effective Rate			7.91%		7.91%
Common securities - Capital Trust VI [Member]
Debt Instrument [Line Items]
Common securties, Balance			10,000,000		10,000,000
Effective Rate			7.91%		7.91%
Junior subordinate debentures - Capital Trust IX, due July 2036 [Member]
Debt Instrument [Line Items]
Subordinated debentures, Balance			150,000,000		150,000,000
Effective Rate			2.03%		2.04%
Common securities - Capital Trust IX [Member]
Debt Instrument [Line Items]
Common securties, Balance			$ 4,640,000		$ 4,640,000
Effective Rate			2.03%		2.04%

[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.