CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
NET (LOSS) / INCOME INCLUDING NCI		$ (1,895,804)	$ 406,365	$ (2,018,718)	$ 645,857
OCI, NET OF TAX
Net unrealized gains on cash flow hedge derivative financial instruments, net of tax	[1]	7,348	1,133	155,653	8,137
Net unrealized (losses) / gains on AFS and HTM investment securities, net of tax		(15,203)	113,290	191,120	204,794
Pension and post-retirement actuarial gains, net of tax		560	6,091	1,120	12,202
TOTAL OTHER COMPREHENSIVE (LOSS) / GAIN, NET OF TAX		(7,295)	120,514	347,893	225,133
COMPREHENSIVE (LOSS) / INCOME		(1,903,099)	526,879	(1,670,825)	870,990
NET (LOSS) / INCOME ATTRIBUTABLE TO NCI		(23,377)	110,743	(19,614)	183,255
COMPREHENSIVE (LOSS) / INCOME ATTRIBUTABLE TO SHUSA		$ (1,879,722)	$ 416,136	$ (1,651,211)	$ 687,735

[1] Excludes $27.0 thousand and $(10.1) million of Other comprehensive loss attributable to NCI for the three-month and six-month periods ended June 30, 2020, respectively, compared to $(10.2) million and $(16.5) million for the corresponding periods in 2019, respectively.