Investments - Additional Information (Detail)		3 Months Ended		6 Months Ended
	Jul. 19, 2016	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2010 USD ($) shares
Schedule of Investments [Line Items]
Equity Method Investment		$ 85,942,000		$ 85,942,000		$ 86,287,000
Marketable Securities		68,726,000		68,726,000		43,787,000
Unfunded commitments for capital contributions		5,132,000		5,132,000
Net realized and unrealized gains (losses) on private equity fund investments, including performance fees		4,764,000	$ 1,815,000	6,131,000	$ 1,326,000
Previously received carried interest subject to repayment		0		0
Assets Held for Sale		6,849,000		6,849,000		0
Liabilities Held for Sale		1,510,000		1,510,000		0
Noncontrolling Interest		237,174,000		237,174,000		202,664,000
Participation in Successor Funds		12,000,000		12,000,000
Cost Method Investments			1,079,000		1,079,000
Income (loss) from equity method investments		1,664,000	1,998,000	2,951,000	3,105,000
Variable Interest Entity, Primary Beneficiary [Member]
Schedule of Investments [Line Items]
Consolidated assets		148,727,000		148,727,000		151,583,000
Consolidated liabilities		84,540,000		84,540,000		110,424,000
Atalanta Sosnoff [Member]
Schedule of Investments [Line Items]
Equity Method Investment		$ 23,387,000		$ 23,387,000		23,990,000
Equity method investment (as a percent)		49.00%		49.00%
Income (loss) from equity method investments		$ 143,000		$ 348,000
EMCP II [Member]
Schedule of Investments [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid					3,194,000
Trilantic IV [Member]
Schedule of Investments [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid					1,650,000
EMP III [Member]
Schedule of Investments [Line Items]
Noncontrolling Interest		6,126,000		6,126,000
EMP III [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Schedule of Investments [Line Items]
Consolidated assets		6,572,000		6,572,000		6,030,000
Consolidated liabilities		83,000		83,000		164,000
Trilantic [Member]
Schedule of Investments [Line Items]
Issued LP Units (in shares) | shares										500,000
Limited partnership investment										$ 16,090,000
G5 Evercore [Member]
Schedule of Investments [Line Items]
Equity Method Investment		$ 24,665,000		$ 24,665,000		20,730,000
Equity method investment (as a percent)		49.00%		49.00%
Income (loss) from equity method investments		$ 277,000	708,000	$ 29,000	651,000
ABS [Member]
Schedule of Investments [Line Items]
Equity Method Investment		$ 37,890,000		$ 37,890,000		41,567,000
Equity method investment (as a percent)		45.00%		45.00%
Income (loss) from equity method investments		$ 1,244,000	1,290,000	$ 2,574,000	2,454,000
ECP II [Member]
Schedule of Investments [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid					3,000,000
CSI Capital [Member]
Schedule of Investments [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid					2,750,000
Noncontrolling Interest [Member]
Schedule of Investments [Line Items]
Noncontrolling Interest		237,174,000	197,109,000	$ 237,174,000	197,109,000	202,664,000	$ 160,952,000
Minimum [Member] | ECP II [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Schedule of Investments [Line Items]
Percent ownership of carried interest				8.00%
Maximum [Member] | ECP II [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Schedule of Investments [Line Items]
Percent ownership of carried interest				9.00%
Equity Method Investments [Member]
Schedule of Investments [Line Items]
Amortization of Intangible Assets		884,000	$ 621,000	$ 1,764,000	$ 1,242,000
EMCP III [Member]
Schedule of Investments [Line Items]
Subscribed capital commitments								$ 201,000,000
EMCP III [Member] | EMP III [Member]
Schedule of Investments [Line Items]
Capital commitment								10,750,000
Unfunded commitments for capital contributions		3,675,000		3,675,000
EMCP III [Member] | Parent [Member]
Schedule of Investments [Line Items]
Capital commitment								1,000,000
Unfunded commitments for capital contributions		300,000		300,000
EMCP III [Member] | Noncontrolling Interest [Member]
Schedule of Investments [Line Items]
Capital commitment								9,750,000
Trilantic [Member]
Schedule of Investments [Line Items]
Investment		12,242,000		12,242,000		12,812,000
Trilantic [Member] | Trilantic IV [Member]
Schedule of Investments [Line Items]
Investment		33,000		33,000		8,000		29,000	$ 1,091,000
Trilantic [Member] | Trilantic V [Member]
Schedule of Investments [Line Items]
Capital commitment		5,000,000		5,000,000
Unfunded commitments for capital contributions		2,550,000		2,550,000
Investment		537,000		537,000		636,000	$ 689,000	$ 825,000
Private Equity Funds [Member]
Schedule of Investments [Line Items]
Equity Method Investment		23,527,000		23,527,000		26,473,000
Private Equity Funds [Member] | ECP II [Member]
Schedule of Investments [Line Items]
Equity Method Investment		959,000		959,000		983,000
Cash		818,000		818,000
Seller Note		61,000		61,000
Marketable Securities		80,000		80,000
Private Equity Funds [Member] | EMCP III [Member]
Schedule of Investments [Line Items]
Equity Method Investment		544,000		544,000		5,786,000
Private Equity Funds [Member] | Trilantic V [Member]
Schedule of Investments [Line Items]
Equity Method Investment		5,039,000		5,039,000		$ 4,117,000
Investments [Member]
Schedule of Investments [Line Items]
Assets Held for Sale		5,847,000		5,847,000
Cash and Cash Equivalents [Member]
Schedule of Investments [Line Items]
Assets Held for Sale		$ 906,000		$ 906,000
Subsequent Event [Member]
Schedule of Investments [Line Items]
Management Fee Period	10 years
Number Of Successor Funds Returning Carried Interest	2
Operational Support Period	18 months