Business Changes and Developments - Additional Information (Details) $ in Thousands, BRL in Millions			3 Months Ended		9 Months Ended	12 Months Ended
	Oct. 18, 2017 USD ($)	Nov. 30, 2016 USD ($)	Jun. 30, 2017	Sep. 30, 2016 USD ($) successor_fund	Sep. 30, 2016 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2017 BRL seat	Dec. 31, 2017 USD ($) seat	Nov. 30, 2017
Business Acquisition [Line Items]
Proceeds from Sale of Business	$ 34,842					$ 34,354	$ 0	$ 0
Business Combination, Contingent Consideration, Asset	$ 488
Gain (Loss) on Disposition of Business						7,808	0	0
Special Charges						25,437	8,100	41,144
Equity Method Investment, Other than Temporary Impairment, Net of Tax							3,980
Cost Method Investments							1,079			$ 1,079
Amortization of Intangible Assets						9,793	11,640	17,458
Impairment of Goodwill						7,107
Goodwill, Impairment Loss, Net of Tax						3,694		9,785
Evercore Trust Company [Member]
Business Acquisition [Line Items]
Assets Deconsolidated						28,523
Liabilities Deconsolidated						1,489	0	0
Special Charges						3,930
G5 [Member]
Business Acquisition [Line Items]
Held-to-maturity Securities, Redemption Value | BRL									BRL 60
Company Seats on Board | seat									1	1
Total Seats on Board | seat									6	6
Held-to-maturity Securities										$ 10,995
Held-to-maturity Securities, Fair Value | BRL									BRL 37
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax						16,266
Atalanta Sosnoff [Member]
Business Acquisition [Line Items]
Liabilities Deconsolidated						0	$ 0	2,074
Equity Method Investment, Ownership Percentage							49.00%		49.00%	49.00%
Fair Value Inputs, Discount Rate (as a percent)		15.50%
Compound Annual Growth Rate, Revenue (as a percent)		6.00%
Equity Method Investment		$ 14,730
Glisco [Member]
Business Acquisition [Line Items]
Assets Deconsolidated					$ 8,302
Liabilities Deconsolidated					2,343	0	$ 2,343	0
Management Fee Period				10 years
Number Of Successor Funds Returning Carried Interest | successor_fund				2
Percent Ownership of Carried Interest				20.00%
Operational Support Period				18 months
Cost Method Investments				$ 2,519	2,519		2,463			$ 2,172
GCP III [Member]
Business Acquisition [Line Items]
Noncontrolling Interest, Decrease from Deconsolidation					$ 5,808
Other Income [Member] | Evercore Trust Company [Member]
Business Acquisition [Line Items]
Gain (Loss) on Disposition of Business						7,808
Other Income [Member] | Glisco [Member]
Business Acquisition [Line Items]
Gain (Loss) on Deconsolidation							406
Institutional Asset Management [Member]
Business Acquisition [Line Items]
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount											17.00%
Investment Management [Member]
Business Acquisition [Line Items]
Gain (Loss) on Disposition of Business						7,808
Special Charges						11,037	8,100	38,993
Investment Management [Member] | Special Charges [Member] | Atalanta Sosnoff [Member]
Business Acquisition [Line Items]
Equity Method Investment, Other than Temporary Impairment							$ 8,100
Investment Management [Member] | Institutional Asset Management [Member]
Business Acquisition [Line Items]
Fair Value Inputs, Discount Rate (as a percent)			17.50%
Compound Annual Growth Rate, Revenue (as a percent)			11.00%
Investment Management [Member] | Institutional Asset Management [Member] | Special Charges [Member]
Business Acquisition [Line Items]
Impairment of Goodwill						7,107		$ 28,500
Goodwill [Member] | Evercore Trust Company [Member]
Business Acquisition [Line Items]
Assets Deconsolidated						$ 28,442