Other comprehensive income (loss) - Components (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Pre-tax amount
Total other comprehensive income (loss), Pre-tax amount		$ (21)	$ 113	$ 357
Tax (expense) benefit
Total other comprehensive income (loss), Tax (expense) benefit		(165)	146	(84)
After-tax amount
Total other comprehensive (loss) income, net of tax	[1]	(186)	259	273
Foreign currency translation
Pre-tax amount
Other comprehensive income (loss), Pre-tax amount		(265)	292	27
Total other comprehensive income (loss), Pre-tax amount		(265)	292	27
Tax (expense) benefit
Other comprehensive income (loss), Tax (expense) benefit		(104)	96	2
Total other comprehensive income (loss), Tax (expense) benefit		(104)	96	2
After-tax amount
Other comprehensive income (loss), After-tax amount		(369)	388	29
Total other comprehensive (loss) income, net of tax		(369)	388	29
Unrealized gain (loss) on assets available-for-sale
Pre-tax amount
Other comprehensive income (loss), Pre-tax amount		243	(114)	322
Reclassification adjustment, Pre-tax amount		(9)	25	(1)
Total other comprehensive income (loss), Pre-tax amount		234	(89)	321
Tax (expense) benefit
Other comprehensive income (loss), Tax (expense) benefit		(60)	37	(83)
Reclassification adjustment, Tax (expense) benefit		2	(6)	0
Total other comprehensive income (loss), Tax (expense) benefit		(58)	31	(83)
After-tax amount
Other comprehensive income (loss), After-tax amount		183	(77)	239
Reclassification adjustment, After-tax amount		(7)	19	(1)
Total other comprehensive (loss) income, net of tax		176	(58)	238
Defined benefit plans
Pre-tax amount
Reclassification adjustment, Pre-tax amount		24	14	13
Total other comprehensive income (loss), Pre-tax amount		24	(97)	2
Tax (expense) benefit
Reclassification adjustment, Tax (expense) benefit		(6)	(10)	(3)
Total other comprehensive income (loss), Tax (expense) benefit		(6)	22	(1)
After-tax amount
Reclassification adjustment, After-tax amount		18	4	10
Total other comprehensive (loss) income, net of tax		18	(75)	1
Prior service cost arising during the period
Pre-tax amount
Other comprehensive income (loss), Pre-tax amount		0	(1)	0
Tax (expense) benefit
Other comprehensive income (loss), Tax (expense) benefit		0	0	0
After-tax amount
Other comprehensive income (loss), After-tax amount		0	(1)	0
Net (loss) gain arising during the period
Pre-tax amount
Other comprehensive income (loss), Pre-tax amount		0	(110)	(11)
Tax (expense) benefit
Other comprehensive income (loss), Tax (expense) benefit		0	32	2
After-tax amount
Other comprehensive income (loss), After-tax amount		0	(78)	(9)
Unrealized gain (loss) on cash flow hedges
Pre-tax amount
Other comprehensive income (loss), Pre-tax amount		(13)	17	6
Reclassification adjustment, Pre-tax amount		(1)	(10)	1
Total other comprehensive income (loss), Pre-tax amount		(14)	7	7
Tax (expense) benefit
Other comprehensive income (loss), Tax (expense) benefit		3	(5)	(4)
Reclassification adjustment, Tax (expense) benefit		0	2	2
Total other comprehensive income (loss), Tax (expense) benefit		3	(3)	(2)
After-tax amount
Other comprehensive income (loss), After-tax amount		(10)	12	2
Reclassification adjustment, After-tax amount		(1)	(8)	3
Total other comprehensive (loss) income, net of tax		(11)	4	5
Unrealized gain (loss) on cash flow hedges | Interest expense
Pre-tax amount
Reclassification adjustment, Pre-tax amount		0	(8)	0
Tax (expense) benefit
Reclassification adjustment, Tax (expense) benefit		0	2	0
After-tax amount
Reclassification adjustment, After-tax amount		0	(6)	0
Unrealized gain (loss) on cash flow hedges | Staff expense
Pre-tax amount
Reclassification adjustment, Pre-tax amount		(1)	(2)	1
Tax (expense) benefit
Reclassification adjustment, Tax (expense) benefit		0	0	2
After-tax amount
Reclassification adjustment, After-tax amount		$ (1)	$ (2)	$ 3

[1] Other comprehensive (loss) income attributable to The Bank of New York Mellon Corporation shareholders was $(184) million for the quarter ended March 31, 2020, $255 million for the quarter ended Dec. 31, 2019 and $271 million for the quarter ended March 31, 2019.