Unconsolidated Entities - Summarized Financial Information of Co-Investment Ventures (Parenthetical) (Detail) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended			9 Months Ended
	Sep. 30, 2012 Venture Receivables Transactions	Sep. 30, 2011 Property	Sep. 30, 2012 Venture Receivables Transactions	Sep. 30, 2011 Property	Dec. 31, 2011 Receivables	Sep. 30, 2011 Prologis [Member]	Sep. 30, 2011 Prologis [Member]	Jun. 30, 2012 U.S. Prologis North American Industrial Fund III [Member]	Dec. 31, 2011 U.S. Prologis North American Industrial Fund III [Member]	Dec. 31, 2011 Prologis SGP Mexico Fund [Member]	Sep. 30, 2012 American [Member]
Schedule Of Equity Method Investments Joint Ventures [Line Items]
Gain on disposition of property	$ (1,300,000)		$ (2,100,000)	$ 33,600,000		$ 13,900,000	$ 13,900,000				$ 10,700,000
Equity method investments, Extinguishment of Debt								25,100,000
Earnings from unconsolidated entities, net	2,563,000	30,975,000	20,447,000	56,015,000				5,000,000
Intercompany notes receivable	19,700,000		19,700,000		41,200,000				21,400,000	19,800,000
Number of receivables
Amount of debt on unconsolidated co-investment ventures			1,400,000,000
Number of co-investment ventures	2		2
Guaranteed debt	28,400,000		28,400,000		28,000,000
Undepreciated cost					$ 277,000,000
Number of types of transactions	3		3
Number of disposed properties		13		13