Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data	Jun. 30, 2011	Dec. 31, 2010
Current Assets:
Allowance for uncollectible accounts receivable	$ (39)	$ (40)
Allowance for obsolescence on expendable parts and supplies inventories	(104)	(104)
Property and Equipment, Net:
Accumulated depreciation and amortization	(4,820)	(4,164)
Other Assets:
Accumulated amortization	$ (565)	$ (530)
Stockholders' Equity:
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	1,500,000,000	1,500,000,000
Common stock, shares issued	860,344,084	847,716,723
Treasury stock, shares	14,281,384	12,993,100