Investments - Carlyle's Income (Loss) from Equity-Method Investments (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule of Investments [Line Items]
Income from equity investments	$ (2.8)	$ 21.5
Corporate Private Equity [Member]
Schedule of Investments [Line Items]
Income from equity investments	12.9	19.9
Global Market Strategies [Member]
Schedule of Investments [Line Items]
Income from equity investments	1.1	0.8
Real Assets [Member]
Schedule of Investments [Line Items]
Income from equity investments	$ (16.8)	$ 0.8