Employee Benefit Plans	12 Months Ended
Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Employee Benefit Plans	19. Employee Benefit Plans Deferred Compensation Plans Voluntary Deferred Compensation Plan. The Company adopted a Voluntary Deferred Compensation Plan (“VDCP”) that allows eligible employees in the United States to elect to defer between 1% and 100% of their annual cash incentive compensation. The participants must specify a deferral period of up to 10 years from the year of deferral and additionally, elect to receive distributions in the form of a lump sum or in up to 10 annual installments. The Company may fund the obligation through the rabbi trust on behalf of the plan’s participants. The rabbi trust established for the VDCP, with assets totaling $23 million and $34 million at December 31, 2019 and 2018, respectively, is reflected in investments on the consolidated statements of financial condition. Such investments are classified as trading investments. The liability balance of $80 million and $71 million at December 31, 2019 and 2018, respectively, is reflected on the consolidated statements of financial condition as accrued compensation and benefits. Earnings in the rabbi trust, including unrealized appreciation or depreciation, are reflected as nonoperating income (expense) and changes in the liability are reflected as employee compensation and benefits expense on the consolidated statements of income. Leadership Retention Carry Plan. In 2019, the Company adopted a carried interest retention incentive program referred to as the BlackRock Leadership Retention Carry Plan, pursuant to which senior-level employees (but not including the Chief Executive Officer), as may be determined by the Company from time to time, will be eligible to receive a portion of the cash payments, based on their percentage points, in the total carried interest distributions payable to the Company from participating carry funds. Cash payments, if any, with respect to these percentage points will be made following the recipient’s termination of employment due to qualified retirement, death or disability, subject to his or her execution of a release of claims and continued compliance with his or her restrictive covenant obligations following termination. There was no impact to the consolidated financial statements. Other Deferred Compensation Plans. The Company has additional compensation plans for the purpose of providing deferred compensation and retention incentives to certain employees. For these plans, the final value of the deferred amount to be distributed in cash upon vesting is associated with investment returns of certain investment funds. The liabilities for these plans were $311 million and $236 million at December 31, 2019 and 2018, respectively, and are reflected in the consolidated statements of financial condition as accrued compensation and benefits. In January 2020, the Company granted approximately $137 million of additional deferred compensation that will fluctuate with investment returns and will vest ratably over three years from the date of grant. Defined Contribution Plans The Company has several defined contribution plans primarily in the United States and United Kingdom. Certain of the Company’s US employees participate in a defined contribution plan. Employee contributions of up to 8% of eligible compensation, as defined by the plan and subject to Internal Revenue Code limitations, are matched by the Company at 50% up to a maximum of $5,000 annually. In addition, the Company makes an annual retirement contribution to eligible participants equal to 3-5% of eligible compensation. The Company’s contribution expense related to this plan was $66 million in 2019, $63 million in 2018, and $78 million in 2017. Certain UK wholly owned subsidiaries of the Company contribute to defined contribution plans for their employees. The contributions range between 6% and 15% of each employee’s eligible compensation. The Company’s contribution expense related to these plans was $41 million in 2019, $35 million in 2018, and $29 million in 2017. In addition, the contribution expense related to defined contribution plans in other regions was $29 million in 2019, $22 million in 2018 and $21 million in 2017. Defined Benefit Plans. The Company has several defined benefit pension plans primarily in Japan and Germany. All accrued benefits under the Germany defined benefit plan are currently frozen and the plan is closed to new participants. The participant benefits under the Germany plan will not change with salary increases or additional years of service. At December 31, 2019 and 2018, the plan assets for these plans were approximately $28 million and $26 million, respectively. The underfunded obligations at December 31, 2019 and 2018 were not material. Benefit payments for the next five years and in aggregate for the five years thereafter are not expected to be material.

Employee Benefit Plans

12 Months Ended

Dec. 31, 2019

Compensation And Retirement Disclosure [Abstract]

19. Employee Benefit Plans

Deferred Compensation Plans

Voluntary Deferred Compensation Plan. The Company adopted a Voluntary Deferred Compensation Plan (“VDCP”) that allows eligible employees in the United States to elect to defer between 1% and 100% of their annual cash incentive compensation. The participants must specify a deferral period of up to 10 years from the year of deferral and additionally, elect to receive distributions in the form of a lump sum or in up to 10 annual installments. The Company may fund the obligation through the rabbi trust on behalf of the plan’s participants.

The rabbi trust established for the VDCP, with assets totaling $23 million and $34 million at December 31, 2019 and 2018, respectively, is reflected in investments on the consolidated statements of financial condition. Such investments are classified as trading investments. The liability balance of $80 million and $71 million at December 31, 2019 and 2018, respectively, is reflected on the consolidated statements of financial condition as accrued compensation and benefits. Earnings in the rabbi trust, including unrealized appreciation or depreciation, are reflected as nonoperating income (expense) and changes in the liability are reflected as employee compensation and benefits expense on the consolidated statements of income.

Leadership Retention Carry Plan. In 2019, the Company adopted a carried interest retention incentive program referred to as the BlackRock Leadership Retention Carry Plan, pursuant to which senior-level employees (but not including the Chief Executive Officer), as may be determined by the Company from time to time, will be eligible to receive a portion of the cash payments, based on their percentage points, in the total carried interest distributions payable to the Company from participating carry funds. Cash payments, if any, with respect to these percentage points will be made following the recipient’s termination of employment due to qualified retirement, death or disability, subject to his or her execution of a release of claims and continued compliance with his or her restrictive covenant obligations following termination. There was no impact to the consolidated financial statements.

Other Deferred Compensation Plans. The Company has additional compensation plans for the purpose of providing deferred compensation and retention incentives to certain employees. For these plans, the final value of the deferred amount to be distributed in cash upon vesting is associated with investment returns of certain investment funds. The liabilities for these plans were $311 million and $236 million at December 31, 2019 and 2018, respectively, and are reflected in the consolidated statements of financial condition as accrued compensation and benefits. In January 2020, the Company granted approximately $137 million of additional deferred compensation that will fluctuate with investment returns and will vest ratably over three years from the date of grant.

Defined Contribution Plans

The Company has several defined contribution plans primarily in the United States and United Kingdom.

Certain of the Company’s US employees participate in a defined contribution plan. Employee contributions of up to 8% of eligible compensation, as defined by the plan and subject to Internal Revenue Code limitations, are matched by the Company at 50% up to a maximum of $5,000 annually. In addition, the Company makes an annual retirement contribution to eligible participants equal to 3-5% of eligible compensation. The Company’s contribution expense related to this plan was $66 million in 2019, $63 million in 2018, and $78 million in 2017.

Certain UK wholly owned subsidiaries of the Company contribute to defined contribution plans for their employees. The contributions range between 6% and 15% of each employee’s eligible compensation. The Company’s contribution expense related to these plans was $41 million in 2019, $35 million in 2018, and $29 million in 2017.

In addition, the contribution expense related to defined contribution plans in other regions was $29 million in 2019, $22 million in 2018 and $21 million in 2017.

Defined Benefit Plans. The Company has several defined benefit pension plans primarily in Japan and Germany. All accrued benefits under the Germany defined benefit plan are currently frozen and the plan is closed to new participants. The participant benefits under the Germany plan will not change with salary increases or additional years of service. At December 31, 2019 and 2018, the plan assets for these plans were approximately $28 million and $26 million, respectively. The underfunded obligations at December 31, 2019 and 2018 were not material. Benefit payments for the next five years and in aggregate for the five years thereafter are not expected to be material.