Unconsolidated Entities - Summarized Financial Information of Co-Investment Ventures (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	$ 443.8	$ 341.7	$ 819.6	$ 711.9
Net earnings (2)	25.9	(4.6)	91.0	14.6
Total assets	23,133.7	17,612.6	23,133.7	17,612.6
Amounts due to (from) us (3)	259.9	72.9	259.9	72.9
Third party debt (4)	7,994.2	7,192.6	7,994.2	7,192.6
Total liabilities	9,390.4	8,186.7	9,390.4	8,186.7
Noncontrolling interest	10.9	8.9	10.9	8.9
Venture partners' equity	13,732.4	9,417.0	13,732.4	9,417.0
Our weighted average ownership (5)	2840000000.00%	2510000000.00%	2840000000.00%	2510000000.00%
Our investment balance (6)	3,708.2	2,013.1	3,708.2	2,013.1
Deferred gains, net of amortization (7)	396.7	329.6	396.7	329.6
Americas [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	183.1	185.8	365.2	396.2
Net earnings (2)	3.5	(28.0)	33.8	(38.1)
Total assets	9,074.3	9,070.4	9,074.3	9,070.4
Amounts due to (from) us (3)	26.9	31.9	26.9	31.9
Third party debt (4)	3,950.2	3,835.5	3,950.2	3,835.5
Total liabilities	4,160.2	4,170.4	4,160.2	4,170.4
Noncontrolling interest	1.5	1.4	1.5	1.4
Venture partners' equity	4,912.6	4,898.6	4,912.6	4,898.6
Our weighted average ownership (5)	2160000000.00%	2320000000.00%	2160000000.00%	2320000000.00%
Our investment balance (6)	1,106.7	1,111.8	1,106.7	1,111.8
Deferred gains, net of amortization (7)	145.3	147.9	145.3	147.9
Europe [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	206.9	120.9	355.3	245.9
Net earnings (2)	14.2	24.3	44.8	48.0
Total assets	9,937.4	6,605.2	9,937.4	6,605.2
Amounts due to (from) us (3)	79.2	33.3	79.2	33.3
Third party debt (4)	2,639.5	2,384.2	2,639.5	2,384.2
Total liabilities	3,647.4	2,953.8	3,647.4	2,953.8
Noncontrolling interest	9.4	7.5	9.4	7.5
Venture partners' equity	6,280.6	3,643.9	6,280.6	3,643.9
Our weighted average ownership (5)	3960000000.00%	2970000000.00%	3960000000.00%	2970000000.00%
Our investment balance (6)	2,174.0	722.8	2,174.0	722.8
Deferred gains, net of amortization (7)	181.6	181.6	181.6	181.6
Asia [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Revenues	53.8	35.0	99.1	69.8
Net earnings (2)	8.2	(0.9)	12.4	4.7
Total assets	4,122.0	1,937.0	4,122.0	1,937.0
Amounts due to (from) us (3)	153.8	7.7	153.8	7.7
Third party debt (4)	1,404.5	972.9	1,404.5	972.9
Total liabilities	1,582.8	1,062.5	1,582.8	1,062.5
Noncontrolling interest	0		0
Venture partners' equity	2,539.2	874.5	2,539.2	874.5
Our weighted average ownership (5)	1720000000.00%	1920000000.00%	1720000000.00%	1920000000.00%
Our investment balance (6)	427.5	178.5	427.5	178.5
Deferred gains, net of amortization (7)	$ 69.8	$ 0.1	$ 69.8	$ 0.1