Unconsolidated Entities - Summarized Financial Information of Co-Investment Ventures (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	$ 375.8	$ 370.5
Net earnings (loss)	58.6	19.2
Total assets	22,693.9	17,612.6
Amounts due to (from) us	160.7	72.9
Third party debt	8,228.0	7,192.6
Total liabilities	9,649.2	8,186.7
Noncontrolling interest	8.6	8.9
Venture partners' equity	13,036.1	9,417.0
Our weighted average ownership	27.00%	25.10%
Our investment balance	3,458.2	2,013.1
Deferred gains, net of amortization	387.4	329.6
Americas [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	182.1	210.7
Net earnings (loss)	30.3	(10.1)
Total assets	9,329.0	9,070.4
Amounts due to (from) us	37.4	31.9
Third party debt	3,873.9	3,835.5
Total liabilities	4,224.6	4,170.4
Noncontrolling interest	1.3	1.4
Venture partners' equity	5,103.1	4,898.6
Our weighted average ownership	21.30%	23.20%
Our investment balance	1,124.6	1,111.8
Deferred gains, net of amortization	147.0	147.9
Europe [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	148.4	125.0
Net earnings (loss)	24.1	23.7
Total assets	9,698.2	6,605.2
Amounts due to (from) us	84.4	33.3
Third party debt	2,654.6	2,384.2
Total liabilities	3,582.7	2,953.8
Noncontrolling interest	7.3	7.5
Venture partners' equity	6,108.2	3,643.9
Our weighted average ownership	36.80%	29.70%
Our investment balance	2,041.6	722.8
Deferred gains, net of amortization	182.5	181.6
Asia [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	45.3	34.8
Net earnings (loss)	4.2	5.6
Total assets	3,666.7	1,937.0
Amounts due to (from) us	38.9	7.7
Third party debt	1,699.5	972.9
Total liabilities	1,841.9	1,062.5
Venture partners' equity	1,824.8	874.5
Our weighted average ownership	17.00%	19.20%
Our investment balance	292.0	178.5
Deferred gains, net of amortization	$ 57.9	$ 0.1