Strategic Initiatives - Restructuring Liability (Details) - USD ($) $ in Millions		3 Months Ended	6 Months Ended
		Jun. 30, 2020	Jun. 30, 2020
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period		$ 33	$ 0
Restructuring costs recorded during the period		13	46
Restructuring costs paid during the period		(1)	(1)
Restructuring liability at end of period		45	45
Severance and Other Employee Costs
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	[1]	9	0
Restructuring costs recorded during the period	[1]	13	22
Restructuring costs paid during the period	[1]	0	0
Restructuring liability at end of period	[1]	22	22
Lease Termination and Associated Costs
Restructuring Reserve [Roll Forward]
Restructuring liability at beginning of period	[2]	24	0
Restructuring costs recorded during the period	[2]	0	24
Restructuring costs paid during the period	[2]	(1)	(1)
Restructuring liability at end of period	[2]	$ 23	$ 23

[1] and other employee costs are included in salaries and employee benefits in the consolidated statement of income (loss). The majority of these costs were reported in the Wealth and Personal Banking and the Global Banking and Markets business segments for segment reporting purposes. Not included in these costs are allocated severance costs from HSBC Technology & Services ("HTSU") discussed further below.

[2] Primarily includes real estate taxes, service charges and decommissioning costs. Lease termination and associated costs are included in occupancy expense, net in the consolidated statement of income (loss) and were reported in the Corporate Center business segment for segment reporting purposes.