Condensed Consolidated Statements of Financial Condition - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 5,978	$ 6,894
Accounts receivable	2,677	2,699
Investments	2,050	1,981
Separate account assets	142,871	149,937
Separate account collateral held under securities lending agreements	27,247	24,190
Property and equipment (net of accumulated depreciation of $698 and $658 at March 31,2018 and December 31, 2017, respectively)	589	592
Intangible assets (net of accumulated amortization of $210 and $219 at March 31, 2018 and December 31, 2017, respectively)	17,378	17,389
Goodwill	13,217	13,220
Other assets	2,157	1,636
Total assets	216,017	220,241
Liabilities
Accrued compensation and benefits	788	2,153
Accounts payable and accrued liabilities	1,421	1,161
Liabilities of consolidated variable interest entities	425	369
Borrowings	5,036	5,014
Separate account liabilities	142,871	149,937
Separate account collateral liabilities under securities lending agreements	27,247	24,190
Deferred income tax liabilities	3,516	3,527
Other liabilities	2,130	1,626
Total liabilities	183,434	187,977
Commitments and contingencies (Note 12)
Temporary equity
Redeemable noncontrolling interests	561	416
Permanent Equity
Shares authorized: 500,000,000 at March 31, 2018 and December 31, 2017; Shares issued: 171,252,185 at March 31, 2018 and December 31, 2017; Shares outstanding: 160,308,362 and 159,977,115 at March 31, 2018 and December 31, 2017, respectively	2	2
Preferred stock (Note 17)	0	0
Additional paid-in capital	18,856	19,256
Retained earnings	17,529	16,939
Accumulated other comprehensive loss	(301)	(432)
Treasury stock, common, at cost (10,943,823 and 11,275,070 shares held at March 31, 2018 and December 31, 2017, respectively)	(4,108)	(3,967)
Total BlackRock, Inc. stockholders’ equity	31,978	31,798
Nonredeemable noncontrolling interests	44	50
Total permanent equity	32,022	31,848
Total liabilities, temporary equity and permanent equity	216,017	220,241
Consolidated Variable Interest Entities [Member]
Assets
Cash and cash equivalents	103	144
Investments	1,637	1,493
Other assets	113	66
Liabilities
Total liabilities	425	369
Permanent Equity
Nonredeemable noncontrolling interests	$ 518	$ 375

Separate account collateral liabilities under securities lending agreements.

No definition available.

Name:	blk_SeparateAccountCollateralLiabilitiesUnderSecuritiesLendingAgreements
Namespace Prefix:	blk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Sum of the carrying values as of the balance sheet date of obligations incurred through that date, including liabilities incurred and payable to vendors for goods and services received, taxes, interest, rent and utilities, compensation costs, payroll taxes and fringe benefits (other than pension and postretirement obligations), contractual rights and obligations, and statutory obligations.