Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2019

Accounting Policies [Abstract]

Summary of Commission Revenue by Fee Type

The following table presents commission revenue by fee type for the three and nine months ended September 30, 2019 and 2018:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2019		2018		2019		2018
	(In thousands)
Commission revenue by fee type
Variable transaction fees
Disclosed trading	$	69,541	$	49,727	$	202,905	$	172,443
Open Trading - matched principal trading		26,444		16,228		72,934		44,943
Total variable transaction fees		95,985		65,955		275,839		217,386
Distribution fees and unused minimum fees		23,884		24,558		70,914		72,012
Total commissions	$	119,869	$	90,513	$	346,753	$	289,398

Summary of Information Services Revenue by Timing of Recognition

The following table presents information services revenue by timing of recognition for the three and nine months ended September 30, 2019 and 2018:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2019		2018		2019		2018
	(In thousands)
Information services revenue by timing of recognition
Services transferred over time	$	7,203	$	7,029	$	21,472	$	20,652
Services transferred at a point in time		490		145		743		518
Total information services revenues	$	7,693	$	7,174	$	22,215	$	21,170

Summary of Post-Trade Services Revenue by Timing of Recognition

The following table presents post-trade services revenue by timing of recognition for the three and nine months ended September 30, 2019 and 2018:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2019		2018		2019		2018
	(In thousands)
Post-trade services revenue by timing of recognition
Services transferred over time	$	3,775	$	3,463	$	11,811	$	11,370
Services transferred at a point in time		9		12		29		301
Total post-trade services revenues	$	3,784	$	3,475	$	11,840	$	11,671

Summary of Revenue Recognized from Contract Liabilities and Remaining Balance

The revenue recognized from contract liabilities and the remaining balance is shown below:

	December 31, 2018		Payments received in advance of services to be performed			Revenue recognized for services performed during the period				Foreign Currency Translation				September 30, 2019
	(In thousands)
Information services	$	1,959		$	6,030		$	(5,437	)		$	—			$	2,552
Post-trade services		851			9,538			(9,180	)			(30	)			1,179
Total deferred revenue	$	2,810		$	15,568		$	(14,617	)		$	(30	)		$	3,731