As of March 26, 2021 and December 31, 2020, collateral held for receivables from clients was $4,058 and $4,035, respectively, and collateral held for securities purchased under agreements to resell was $1,789 and $1,743, respectively. As the fair value of the collateral either exceeded or was at least 100% of the amortized cost, the expected credit loss was zero for each period. Additionally, partnership loan values remained below the value of capital allocated to partners, resulting in an expected credit loss of zero as of March 26, 2021 and December 31, 2020.

As of March 26, 2021, December 31, 2020 and December 31, 2019, $615, $563 and $470, respectively, of the receivable from clients balance and $302, $285 and $291, respectively, of the receivable from mutual funds, insurance companies and other balance related to revenue contracts with customers. The related fees are paid out of client accounts or third-party products consisting of cash and securities, and the collateral value of those accounts continues to exceed the amortized cost basis of these receivables, resulting in a remote risk of loss. The expected credit loss for receivables from contracts with customers was zero as of March 26, 2020 and December 31, 2020.

The Partnership derived 13% and 14% of its total revenue for the three-month periods ended March 26, 2021 and March 27, 2020, respectively, from one mutual fund company. The revenue generated from this company relates to business conducted with the Partnership's U.S. segment.

The following table shows the Partnership's disaggregated revenue information. See Note 8 for segment information.

	Three Months Ended March 26, 2021						Three Months Ended March 27, 2020
	U.S.		Canada		Total		U.S.		Canada		Total
Fee revenue:
Asset-based fee revenue:
Advisory programs fees	$	1,640	$	27	$	1,667	$	1,281	$	19	$	1,300
Service fees		366		25		391		316		24		340
Other asset-based fees		151		—		151		166		—		166
Total asset-based fee revenue		2,157		52		2,209		1,763		43		1,806
Account and activity fee revenue:
Shareholder accounting services fees		107		—		107		109		—		109
Other account and activity fee revenue		59		4		63		59		3		62
Total account and activity fee revenue		166		4		170		168		3		171
Total fee revenue		2,323		56		2,379		1,931		46		1,977
Trade revenue:
Commissions		419		14		433		464		13		477
Principal transactions		9		—		9		15		1		16
Total trade revenue		428		14		442		479		14		493
Total revenue from customers		2,751		70		2,821		2,410		60		2,470
Net interest and dividends and other revenue		28		4		32		13		8		21
Net revenue	$	2,779	$	74	$	2,853	$	2,423	$	68	$	2,491