Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data	Sep. 30, 2011	Dec. 31, 2010
Current assets:
Allowance for doubtful accounts receivable	$ 40	$ 45
Allowance for doubtful notes receivable securitized vacation ownership	$ 9	$ 10
Stockholders' equity:
Common stock par value	$ 0.01	$ 0.01
Common Stock, authorized	1,000,000,000	1,000,000,000
Common Stock, outstanding	195,342,872	192,970,437