Investments - Partnership's Equity Method Investees, Summarized Balance Sheet Information (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Schedule of Investments [Line Items]
Investments	$ 58,980.2	$ 70,711.5
Total assets	64,487.1	75,188.4
Debt	1,970.6	1,386.5
Other liabilities	889.8	2,335.5
Total liabilities	2,860.4	3,722.0
Partners’ capital	61,626.7	71,466.4
Corporate Private Equity
Schedule of Investments [Line Items]
Investments	35,535.4	38,498.0
Total assets	39,489.9	41,636.9
Debt	281.5	276.3
Other liabilities	540.7	1,445.3
Total liabilities	822.2	1,721.6
Partners’ capital	38,667.7	39,915.3
Global Market Strategies
Schedule of Investments [Line Items]
Investments	2,262.1	2,398.4
Total assets	2,604.0	2,542.2
Debt	176.6	67.3
Other liabilities	17.7	15.0
Total liabilities	194.3	82.3
Partners’ capital	2,409.7	2,459.9
Real Assets
Schedule of Investments [Line Items]
Investments	21,182.7	29,815.1
Total assets	22,393.2	31,009.3
Debt	1,512.5	1,042.9
Other liabilities	331.4	875.2
Total liabilities	1,843.9	1,918.1
Partners’ capital	$ 20,549.3	$ 29,091.2