Condensed Consolidated Statements Of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Net income	$ 655		$ 570		$ 1,790		$ 1,756
Other comprehensive income:
Change in net unrealized gains (losses) from available-for-sale investments, net of tax: Unrealized holding gains (losses), net of tax	10		(5)		12		(6)
Less: reclassification adjustment included in net income	(4)		(2)		(5)
Net change in unrealized gains (losses) from available-for-sale investments, net of tax(1)	14	[1]	(3)	[1]	17	[1]	(6)	[1]
Minimum pension liability adjustment					(1)
Foreign currency translation adjustments	54		(67)		53		(8)
Other comprehensive income (loss)	68		(70)		69		(14)
Comprehensive income	723		500		1,859		1,742
Less: Comprehensive income (loss) attributable to non-controlling interests	13		(25)		22		(26)
Comprehensive income attributable to BlackRock, Inc.	$ 710		$ 525		$ 1,837		$ 1,768

[1] The tax benefit (expense) on unrealized holding gains (losses) was ($7) million and $2 million during the three months ended September 30, 2012 and 2011, respectively, and ($8) million and $3 million during the nine months ended September 30, 2012 and 2011, respectively.