The following table presents the Company’s total revenues separated between revenues from contracts with customers and other sources of revenues (in thousands):

	Year Ended December 31, 2019		Year Ended December 31, 2018
Revenue from contracts with customers:
Commissions	$	1,645,818	$	1,511,522
Data, software, and post-trade		73,166		65,185
Fees from related parties		29,442		24,076
Other revenues		12,806		3,837
Total revenue from contracts with customers		1,761,232		1,604,620
Other sources of revenue:
Principal transactions		321,923		313,053
Interest income		18,319		14,404
Other revenues		2,757		5,733
Total revenues	$	2,104,231	$	1,937,810

As discussed in Note 1—“Organization and Basis of Presentation”, the Company adopted the new revenue recognition standard as of January 1, 2018. There was no significant impact to the Company’s consolidated financial statements for the periods presented as a result of applying the new revenue recognition standard.

Refer to Note 3—“Summary of Significant Accounting Policies” for detailed information on the recognition of the Company’s revenues from contracts with customers.

Refer to Note 23—“Segment, Geographic and Product Information” for a further discussion on the allocation of revenues to geographic regions.

The timing of our revenue recognition may differ from the timing of payment by our customers. The Company records a receivable when revenue is recognized prior to payment and the Company has an unconditional right to payment. Alternatively, when payment precedes the provision of the related services, the Company records deferred revenue until the performance obligations are satisfied.

The Company had receivables related to revenues from contracts with customers of $778.4 million and $516.1 million at December 31, 2019 and December 31, 2018 respectively. The Company had no impairments related to these receivables during the years ended December 31, 2019 and 2018.

The Company’s deferred revenue primarily relates to customers paying in advance or billed in advance where the performance obligation has not yet been satisfied. Deferred revenue at December 31, 2019 and December 31, 2018 was $12.9 million and $12.8 million, respectively. During the year ended December 31, 2019, the Company recognized revenue of $9.1 million that was recorded as deferred revenue at the beginning of the period.

The Company capitalizes costs to fulfill contracts associated with different lines of its business where the revenue is recognized at a point in time and the costs are determined to be recoverable. Capitalized costs to fulfill a contract are recognized at the point in time that the related revenue is recognized. At December 31, 2019, there were $1.4 million of capitalized costs recognized to fulfill a contract. At December 31, 2018, there were no capitalized costs recorded to fulfill a contract.