Commitments and Contingencies - Additional Information (Detail) (USD $)	0 Months Ended					0 Months Ended		9 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	9 Months Ended
	Jul. 15, 2009	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 LFB [Member]	Sep. 30, 2014 LFNY [Member]	Jul. 15, 2009 Initial Shares [Member]	Jul. 15, 2009 Earnout Shares [Member]	Sep. 30, 2014 Initial Shares and Earnout Shares [Member]	Dec. 31, 2013 Initial Shares and Earnout Shares [Member]	Mar. 31, 2013 Class A Common Stock [Member]	Dec. 31, 2012 Class A Common Stock [Member]	Sep. 30, 2014 Class A Common Stock [Member] Maximum [Member]
Other Commitments [Line Items]
Guarantees indemnifications		$ 4,851,000
Collateral/counter-guarantees		4,357,000
Aggregate fair value of consideration recognized by the company at acquisition date	61,624,000
Additional shares issued and subject to earnout criteria and payable over time						1,142,857	1,142,857
Initial and Earnout shares issuable on contingent basis								913,722	913,722
Initial and Earnout shares earned								1,371,992	1,371,992
Initial and Earnout shares became settled		1,041,436	1,029,006
Common stock issuable on non-contingent basis											170,988
Common stock issued on non-contingent basis										170,988
Common stock issuable on contingent basis												202,650
Underwriting commitments				$ 0	$ 0