Regulatory Authorities - Additional Information (Detail)	Dec. 31, 2022 USD ($)
LFNY [Member]
Regulatory Requirements [Line Items]
Specified fixed percentage, minimum required capital	6.67%
Minimum net capital requirement as defined under exchange act	$ 5,000
Regulatory capital	110,275,000
Regulatory capital in excess of minimum requirement	$ 105,521,000
Aggregate indebtedness to net capital ratio	0.64
LFNY [Member] | Maximum [Member]
Regulatory Requirements [Line Items]
Aggregate indebtedness to net capital ratio	15
U.K. Subsidiaries [Member]
Regulatory Requirements [Line Items]
Regulatory capital	$ 176,397,000
Regulatory capital in excess of minimum requirement	119,088,000
CFLF [Member]
Regulatory Requirements [Line Items]
Regulatory capital	152,442,000
Regulatory capital in excess of minimum requirement	74,403,000
Combined European Regulated Group [Member]
Regulatory Requirements [Line Items]
Regulatory capital	176,343,000
Regulatory capital in excess of minimum requirement	89,905,000
Other U.S. and Non-U.S. Subsidiaries [Member]
Regulatory Requirements [Line Items]
Regulatory capital	189,167,000
Regulatory capital in excess of minimum requirement	$ 162,010,000