Commitments and Contingencies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019 USD ($) shares
Business Acquisitions [Member] | Class A Common Stock [Member]
Other Commitments [Line Items]
Number of contingent additional shares earned including dividend equivalent amount | shares	731,822
Business Acquisitions [Member] | Class A Common Stock [Member] | Non-Contingent [Member]
Other Commitments [Line Items]
Business acquisition exchangeable interest into common stock | shares	247,518
LFB [Member]
Other Commitments [Line Items]
Guarantees indemnifications	$ 2,279,000
Collateral/counter-guarantees	2,279,000
Other commitments	0
LFNY [Member]
Other Commitments [Line Items]
Other commitments	$ 0