Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred Stock, par value	$ 0.01	$ 0.01
Preferred Stock, share authorized	100,000.0	100,000.0
Preferred Stock, share issued	0	0
Preferred Stock, share outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	3,200,000,000	3,200,000,000
Common stock, shares issued	1,697,000,000	1,691,000,000
Common stock, shares outstanding	1,118,000,000	1,140,000,000
Treasury stock, shares	578,000,000	550,000,000
Shares held in trust, shares	1,000,000	1,000,000