Components of Other Comprehensive Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Dec. 31, 2011		Mar. 31, 2011
Pre-tax
Foreign currency translation adjustment arising during the period	$ 129		$ (157)		$ 193
Unrealized gain (loss) on assets available-for-sale:
Unrealized gain (loss) arising during period	378		(48)		226
Reclassification adjustment	(40)		3		(5)
Net unrealized gain (loss) on assets available-for-sale	338		(45)		221
Defined benefit plans:
Net loss arising during the period			(741)
Foreign exchange adjustment			(4)
Amortization of prior service credit, net loss and initial obligation included in net periodic benefit cost	44		29		26
Total defined benefit plans	44		(716)		26
Unrealized gain (loss) on cash flow hedges:
Unrealized gain (loss) arising during period	1		(44)		1
Reclassification adjustment	5		(4)
Net unrealized gain (loss) on cash flow hedges	6		(48)		1
Total other comprehensive income (loss)	517		(966)		441
Tax (expense) benefit
Foreign currency translation adjustment arising during the period	43		(13)		45
Unrealized gain (loss) on assets available-for-sale:
Unrealized gain (loss) arising during period	(141)		30		(91)
Reclassification adjustment	16		(1)		3
Net unrealized gain (loss) on assets available-for-sale	(125)		29		(88)
Defined benefit plans:
Net loss arising during the period			296
Foreign exchange adjustment			1
Amortization of prior service credit, net loss and initial obligation included in net periodic benefit cost	(17)		(12)		(9)
Total defined benefit plans	(17)		285		(9)
Unrealized gain (loss) on cash flow hedges:
Unrealized gain (loss) arising during period	(1)		19		(1)
Reclassification adjustment	(2)		2
Net unrealized gain (loss) on cash flow hedges	(3)		21		(1)
Total other comprehensive income (loss)	(102)		322		(53)
After-tax amount
Foreign currency translation adjustment arising during the period	172		(170)		238
Unrealized gain (loss) on assets available-for-sale:
Unrealized gain (loss) arising during period	237		(18)		135
Reclassification adjustment	(24)		2		(2)
Net unrealized gain (loss) on assets available-for-sale	213		(16)		133
Defined benefit plans:
Net loss arising during the period			(445)
Foreign exchange adjustment			(3)
Amortization of prior service credit, net loss and initial obligation included in net periodic benefit cost	27		17		17
Total defined benefit plans	27		(431)		17
Unrealized gain (loss) on cash flow hedges:
Unrealized gain (loss) arising during period			(25)
Reclassification adjustment	3		(2)
Net unrealized gain (loss) on cash flow hedges	3		(27)
Total other comprehensive income (loss)	$ 415	[1]	$ (644)	[1]	$ 388	[1]

[1] Other comprehensive income (loss) attributable to The Bank of New York Mellon Corporation shareholders was $398 million for the quarter ended March 31, 2012, $(623) million for the quarter ended Dec. 31, 2011 and $352 million for the quarter ended March 31, 2011.