Receivables and Revenue - Additional Information (Detail)	3 Months Ended
Mar. 26, 2021 USD ($) Customer	Mar. 27, 2020 Customer	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Receivables And Revenue [Line Items]
Collateral held for receivables from clients	$ 4,058,000,000		$ 4,035,000,000
Collateral held for securities purchased under agreements to resell	$ 1,789,000,000		1,743,000,000
Fair value of collateral as percentage of amortized cost	100.00%
Expected credit loss on collateral held for receivables from clients	$ 0		0
Expected credit loss on partnership loans	0		0
Receivable from clients balance	615,000,000		563,000,000	$ 470,000,000
Fees from mutual fund, insurance companies and other	302,000,000		285,000,000	$ 291,000,000
Expected credit loss for receivables from contracts with customers	$ 0		$ 0
Concentration risk, number of customers \| Customer	1	1
Sales Revenue Net [Member] \| Customer [Member]
Receivables And Revenue [Line Items]
Concentration Risk, Percentage	13.00%	14.00%

Concentration risk, number of customers.

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- Definition

Expected credit loss for receivables from contracts with customers.

+ References

No definition available.

+ Details

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- Definition

Expected credit loss on collateral held for receivables from clients.

+ References

No definition available.

+ Details

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- Definition

Fair value of collateral as percentage of amortized cost.

+ References

No definition available.

+ Details

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- Definition

Fees from mutual fund, insurance companies and other.

+ References

No definition available.

+ Details

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- Definition

Partnership loans expected credit loss.

+ References

No definition available.

+ Details

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- Definition

Receivables and revenue.

+ References

No definition available.

+ Details

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- Definition

Revenue from contract with customer receivables.

+ References

No definition available.

+ Details

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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- Definition

Fair value as of the balance sheet date of customer securities accepted as collateral by the entity that it is permitted by contract or custom to sell or re-pledge to counterparties as collateral.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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- Definition

Fair value as of the balance sheet date of customer securities accepted as collateral by the entity that it has sold or re-pledged to counterparties as collateral.

+ References

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