Summary of Significant Accounting Policies - Additional Information (Details) € in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Jan. 01, 2016 USD ($)	Dec. 31, 2014 EUR (€)	Dec. 31, 2012 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accrued performance fee-related compensation	$ 1,511.9	$ 1,815.4
Percentage of estimated realizable tax benefit to be paid by corporate taxpayers on exchange transactions	85.00%
Percentage of remaining estimated realizable tax benefit on exchange transactions	15.00%
Cash withheld from carried interest distributions for potential giveback obligations	$ 17.3	29.9
Restricted cash for carried interest proceeds for one corporate private equity fund		13.2
Cash received on behalf of a non-consolidated funds	1.5	8.7
Restricted cash included in escrow related to tax contingency		5.4			€ 4.4
Cash received to satisfy collateral requirements	1.8	2.3
Restricted securities of consolidated funds	16.6	12.6
Foreign currency transaction gain (losses) before tax	2.5	8.8	$ 6.3
Partners’ capital appropriated for Consolidated Funds	120.8	184.5
Assets	(32,191.0)	(35,994.3)	(35,622.3)
Liabilities	(23,267.5)	(23,138.3)
Partners' Capital	$ (6,077.6)	$ (9,094.5)	$ (10,377.4)			$ (10,695.4)
Minimum | Subsequent Event | Accounting Standards Update 2015-2
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets				$ 23,000.0
Liabilities				16,000.0
Partners' Capital				4,000.0
Maximum | Subsequent Event | Accounting Standards Update 2015-2
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets				24,000.0
Liabilities				17,000.0
Partners' Capital				$ 5,000.0