Regulatory Authorities - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
EGL [Member]
Regulatory Authorities [Line Items]
Alternative Net Capital Requirement	$ 250,000
Net Capital	52,914,000	74,080,000
Alternative excess net capital	52,664,000	73,830,000
International Strategy & Investment Group LLC [Member]
Regulatory Authorities [Line Items]
Alternative Net Capital Requirement	250,000
Net Capital	11,149,000	7,548,000
Alternative excess net capital	10,899,000	7,298,000
Evercore Trust Company [Member]
Regulatory Authorities [Line Items]
Tier One Capital	5,000,000
Minimum liquid assets, amount	3,500,000
Coverage of operating expenses (in days)	90 days
Collateral held in a segregated account at a third-party depository institution	$ 10,000,000