Condensed Consolidated Statements of Comprehensive Income (Unaudited) - 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	$ (124,437)	$ 160,186	$ (2,361,722)	$ 301,167
Other comprehensive income, net of tax:
Net unrealized gains arising during period from debt securities available for sale	31,715	85,704	131,414	137,404
Less: reclassification adjustment for net gains on sale of debt securities available for sale in net income	2,648	0	17,220	6,834
Net change in net unrealized holding gains on debt securities available for sale	29,067	85,704	114,194	130,570
Change in unamortized net holding gains on debt securities held to maturity	1,705	1,939	3,280	3,682
Less: non-credit related impairment on debt securities held to maturity	0	82	0	82
Change in unamortized non-credit related impairment on debt securities held to maturity	121	132	239	500
Net change in unamortized holding gains on debt securities held to maturity	1,826	1,989	3,519	4,100
Unrealized holding gains arising during period from cash flow hedge instruments	10,933	73,950	285,770	98,003
Change in defined benefit plans	0	0	1,754	3,119
Other comprehensive income, net of tax	41,826	161,643	405,237	235,792
Comprehensive (loss) income	(82,611)	321,829	(1,956,485)	536,959
Less: comprehensive income attributable to noncontrolling interests	472	599	973	1,155
Comprehensive (loss) income attributable to BBVA USA Bancshares, Inc.	$ (83,083)	$ 321,230	$ (1,957,458)	$ 535,804