Investments - Carlyle's Income from Equity-Method Investments (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Investments [Line Items]
Income from equity investments	$ 32.7	$ 70.5	$ 66.3
Corporate Private Equity [Member]
Schedule of Investments [Line Items]
Income from equity investments	35.7	57.3	49.0
Global Market Strategies [Member]
Schedule of Investments [Line Items]
Income from equity investments	1.2	0.9	9.3
Real Assets [Member]
Schedule of Investments [Line Items]
Income from equity investments	$ (4.2)	$ 12.3	$ 8.0