Unconsolidated Entities - Summarized Financial Information of Co-Investment Ventures (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	$ 500.7	$ 443.8	$ 984.1	$ 819.6
Net operating income	382.7	334.1	751.6	608.7
Net earnings (loss)	72.4	25.9	159.2	91.0
Amounts due to us	181.4		181.4		164.0
Third party debt	7,845.2		7,845.2		7,712.5
Total liabilities	9,528.7		9,528.7		9,189.9
Our weighted average ownership	30.70%		30.70%		29.20%
Our investment balance	5,400.3		5,400.3		4,250.0
Deferred gains, net of amortization	412.7		412.7		431.1
Americas [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	178.7	183.1	346.9	365.2
Net operating income	132.2	134.2	251.4	267.3
Net earnings (loss)	(9.7)	3.5	(7.5)	33.8
Amounts due to us	47.1		47.1		10.3
Third party debt	3,334.4		3,334.4		2,999.1
Total liabilities	3,584.1		3,584.1		3,177.1
Our weighted average ownership	27.70%		27.70%		22.70%
Our investment balance	2,067.4		2,067.4		1,194.0
Deferred gains, net of amortization	121.4		121.4		139.6
Europe [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	252.3	206.9	499.0	355.3
Net operating income	196.8	159.4	392.9	264.7
Net earnings (loss)	65.6	14.2	128.2	44.8
Amounts due to us	28.8		28.8		43.7
Third party debt	2,703.8		2,703.8		2,998.2
Total liabilities	3,895.7		3,895.7		4,113.6
Our weighted average ownership	38.70%		38.70%		39.00%
Our investment balance	2,969.4		2,969.4		2,703.3
Deferred gains, net of amortization	198.0		198.0		196.7
Asia [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	69.7	53.8	138.2	99.1
Net operating income	53.7	40.5	107.3	76.7
Net earnings (loss)	16.5	8.2	38.5	12.4
Amounts due to us	105.5		105.5		110.0
Third party debt	1,807.0		1,807.0		1,715.2
Total liabilities	2,048.9		2,048.9		1,899.2
Our weighted average ownership	15.00%		15.00%		15.00%
Our investment balance	363.5		363.5		352.7
Deferred gains, net of amortization	$ 93.3		$ 93.3		$ 94.8