Components of Other Comprehensive Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended						6 Months Ended
	Jun. 30, 2012		Mar. 31, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Pre-tax
Foreign currency translation adjustment arising during the period	$ (223)		$ 129		$ 120		$ (94)		$ 313
Unrealized gain (loss) on assets available-for-sale:
Unrealized gain (loss) arising during period	318		378		244		696		470
Reclassification adjustment	(50)		(40)		(48)		(90)		(53)
Net unrealized gain (loss) on assets available-for-sale	268		338		196		606		417
Defined benefit plans:
Amortization of prior service credit, net loss and initial obligation included in net periodic benefit cost	42		44		28		86		54
Total defined benefit plans	42		44		28		86		54
Unrealized gain (loss) on cash flow hedges:
Unrealized hedge gain (loss) arising during period	8		1		(1)		9
Reclassification adjustment	(9)		5		1		(4)		1
Net unrealized gain (loss) on cash flow hedges	(1)		6				5		1
Total other comprehensive income (loss)	86		517		344		603		785
Tax (expense) benefit
Foreign currency translation adjustment arising during the period	(42)		43		1		1		46
Unrealized gain (loss) on assets available-for-sale:
Unrealized gain (loss) arising during period	(121)		(141)		(85)		(262)		(176)
Reclassification adjustment	15		16		20		31		23
Net unrealized gain (loss) on assets available-for-sale	(106)		(125)		(65)		(231)		(153)
Defined benefit plans:
Amortization of prior service credit, net loss and initial obligation included in net periodic benefit cost	(18)		(17)		(11)		(35)		(20)
Total defined benefit plans	(18)		(17)		(11)		(35)		(20)
Unrealized gain (loss) on cash flow hedges:
Unrealized hedge gain (loss) arising during period	(2)		(1)				(3)		(1)
Reclassification adjustment	3		(2)				1
Net unrealized gain (loss) on cash flow hedges	1		(3)				(2)		(1)
Total other comprehensive income (loss)	(165)		(102)		(75)		(267)		(128)
After-tax amount
Foreign currency translation adjustment arising during the period	(265)		172		121		(93)		359
Unrealized gain (loss) on assets available-for-sale:
Unrealized gain (loss) arising during period	197		237		159		434		294
Reclassification adjustment	(35)		(24)		(28)		(59)		(30)
Net unrealized gain (loss) on assets available-for-sale	162		213		131		375		264
Defined benefit plans:
Amortization of prior service credit, net loss and initial obligation included in net periodic benefit cost	24		27		17		51		34
Total defined benefit plans	24		27		17		51		34
Unrealized gain (loss) on cash flow hedges:
Unrealized hedge gain (loss) arising during period	6				(1)		6		(1)
Reclassification adjustment	(6)		3		1		(3)		1
Net unrealized gain (loss) on cash flow hedges			3				3
Total other comprehensive income (loss)	$ (79)	[1]	$ 415	[1]	$ 269	[1]	$ 336	[1]	$ 657	[1]

[1] Other comprehensive income (loss) attributable to The Bank of New York Mellon Corporation shareholders was $(51) million for the quarter ended June 30, 2012, $398 million for the quarter ended March 31, 2012, $252 million for the quarter ended June 30, 2011, $347 million for the six months ended June 30, 2012 and $604 million for the six months ended June 30, 2011.