Investments - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended							1 Months Ended	3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended			9 Months Ended				9 Months Ended
	Jun. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 EMP III [Member] Variable Interest Entity, Primary Beneficiary [Member]	Dec. 31, 2013 EMP III [Member] Variable Interest Entity, Primary Beneficiary [Member]	Dec. 31, 2010 Trilantic [Member]	Feb. 28, 2010 Trilantic [Member]	Jun. 30, 2014 G5 Evercore [Member]	Sep. 30, 2014 G5 Evercore [Member]	Sep. 30, 2013 G5 Evercore [Member]	Sep. 30, 2014 G5 Evercore [Member]	Sep. 30, 2013 G5 Evercore [Member]	Dec. 31, 2013 G5 Evercore [Member]	Sep. 30, 2014 ABS [Member]	Sep. 30, 2013 ABS [Member]	Sep. 30, 2014 ABS [Member]	Sep. 30, 2013 ABS [Member]	Dec. 31, 2013 ABS [Member]	Sep. 30, 2013 Pan [Member]	Mar. 16, 2013 Pan [Member]	Mar. 15, 2013 Pan [Member]	Dec. 31, 2008 Pan [Member]	Sep. 30, 2014 Minimum [Member] ECP II [Member] Variable Interest Entity, Primary Beneficiary [Member]	Sep. 30, 2014 Maximum [Member] ECP II [Member] Variable Interest Entity, Primary Beneficiary [Member]	Dec. 31, 2013 EMCP III [Member]	Sep. 30, 2014 EMCP III [Member] EMP III [Member]	Dec. 31, 2013 EMCP III [Member] EMP III [Member]	Sep. 30, 2014 EMCP III [Member] Parent [Member]	Dec. 31, 2013 EMCP III [Member] Parent [Member]	Dec. 31, 2013 EMCP III [Member] Noncontrolling Interest [Member]	Sep. 30, 2014 Trilantic [Member]	Dec. 31, 2013 Trilantic [Member]	Dec. 31, 2013 Trilantic [Member] Trilantic IV [Member]	Dec. 31, 2012 Trilantic [Member] Trilantic IV [Member]	Sep. 30, 2014 Trilantic [Member] Trilantic V [Member]	Dec. 31, 2013 Trilantic [Member] Trilantic V [Member]
Schedule of Investments [Line Items]
Subscribed capital commitments																												$ 201,000,000
Capital commitment																														10,750,000		1,000,000	9,750,000					5,000,000
Unfunded commitments for capital contributions		9,177,000		9,177,000																									4,691,000		484,000							3,723,000
Net realized and unrealized gains (losses) on private equity fund investments, including performance fees		1,671,000	2,663,000	5,633,000	5,213,000
Previously received carried interest subject to repayment		2,701,000		2,701,000
Percent ownership of carried interest																										8.00%	9.00%
Consolidated assets							7,342,000	4,287,000
Consolidated liabilities							55,000	32,000
Issued LP Units (in shares)									500,000	500,000
Limited partnership investment		15,369,000		15,369,000		36,805,000			16,090,000
Investment																																		13,603,000	14,145,000	29,000	1,091,000	541,000	825,000
Equity interest issued or issuable (in shares)											131,000			131,000
Equity interest issued or issuable, value											7,232,000
Contingent consideration	7,916,000
Equity method investment (as a percent)												49.00%		49.00%			45.00%		45.00%				68.00%	50.00%
Income (loss) from equity method investments		1,102,000	562,000	3,381,000	2,333,000							(25,000)	(226,000)	(45,000)	(42,000)		1,127,000	788,000	3,426,000	2,430,000		(55,000)
Equity method investment		76,593,000		76,593,000		67,560,000						33,915,000		33,915,000		20,001,000	42,678,000		42,678,000		47,559,000				4,158,000
Amortization of intangible assets		$ 647,000	$ 647,000	$ 1,941,000	$ 1,941,000