Carrying Amount and Fair Value of Certain Financial Assets and Liabilities (Detail) (USD $) In Millions	Sep. 09, 2011	Dec. 31, 2010
Carrying (Reported) Amount, Fair Value Disclosure
Financial assets
Mortgage notes receivable	$ 65	$ 55
Financial liabilities
Senior notes	3,341	3,093
Exchangeable Senior Debentures	925	1,156
Credit facility	119	58
Mortgage debt and other, net of capital leases	1,101	1,110
Portion at Fair Value, Fair Value Disclosure
Financial assets
Mortgage notes receivable	83	77
Financial liabilities
Senior notes	3,440	3,200
Exchangeable Senior Debentures	1,015	1,471
Credit facility	119	58
Mortgage debt and other, net of capital leases	$ 1,116	$ 1,107

Fair Value, Option, Disclosures Not Related to Election, Items Existing at Effective Date, Exchangeable Senior Debentures

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Fair Value, Option, Disclosures Not Related to Election, Items Existing at Effective Date, Financial Assets [Abstract]

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Fair Value, Option, Disclosures Not Related to Election, Items Existing at Effective Date, Financial Liabilities [Abstract]

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Fair Value Option Disclosures Not Related to Election Items Existing At Effective Date Line Of Credit

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Fair Value, Option, Disclosures Not Related to Election, Items Existing at Effective Date, Mortgage Debt and Other, Net of Capital Leases

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Fair Value, Option, Disclosures Not Related to Election, Items Existing at Effective Date, Mortgage Notes Receivable

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Fair Value, Option, Disclosures Not Related to Election, Items Existing at Effective Date, Senior Debt Obligations

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