Unconsolidated Entities - Summarized Financial Information of Co-Investment Ventures (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	$ 483.4	$ 375.8
Net operating income	368.9	274.6
Net earnings	86.8	54.4
Amounts due to us	122.6		164.0
Third party debt	7,383.9		7,712.5
Total liabilities	8,840.9		9,189.9
Our weighted average ownership	29.40%		29.20%
Our investment balance	4,513.2		4,250.0
Deferred gains, net of amortization	427.3		431.1
Americas [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	168.2	182.1
Net operating income	119.2	133.1
Net earnings	2.2	26.1
Amounts due to us	14.7		10.3
Third party debt	2,961.1		2,999.1
Total liabilities	3,110.8		3,177.1
Our weighted average ownership	23.30%		22.70%
Our investment balance	1,225.4		1,194.0
Deferred gains, net of amortization	138.0		139.6
Europe [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	246.7	148.4
Net operating income	196.1	105.3
Net earnings	62.6	24.1
Amounts due to us	8.8		43.7
Third party debt	2,685.2		2,998.2
Total liabilities	3,818.8		4,113.6
Our weighted average ownership	38.90%		39.00%
Our investment balance	2,943.8		2,703.3
Deferred gains, net of amortization	195.7		196.7
Asia [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	68.5	45.3
Net operating income	53.6	36.2
Net earnings	22.0	4.2
Amounts due to us	99.1		110.0
Third party debt	1,737.6		1,715.2
Total liabilities	1,911.3		1,899.2
Our weighted average ownership	15.00%		15.00%
Our investment balance	344.0		352.7
Deferred gains, net of amortization	$ 93.6		$ 94.8