Subsequent Events (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended		0 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Apr. 30, 2014 Subsequent Event [Member]	Apr. 30, 2014 Subsequent Event [Member] Purchase From Accelerated Share Repurchase [Member]	May 06, 2014 Subsequent Event [Member] Senior Notes Due 2019 [Member]	Apr. 30, 2014 Subsequent Event [Member] Senior Notes Due 2019 [Member]	May 06, 2014 Subsequent Event [Member] Senior Notes Due 2019 [Member] Over Allotment Option [Member]	Apr. 30, 2014 Subsequent Event [Member] Privately Negotiated Transaction [Member]
Subsequent Event [Line Items]
Days Of Additional Interest To Remedy Default			270 days
Convertible debt						$ 1,250,000,000
Stated interest rate percentage						0.50%
Additional amount to cover over-allotment					187,500,000
Proceeds from convertible debt						1,230,000,000	184,900,000
Payments for (proceeds from) hedge, investing activities					10,800,000	71,800,000
Stock repurchase program, authorized amount	5,400,000,000					1,500,000,000
Amount used to repurchase stock	0	61,364,000						101,000,000
Stock repurchased during period, value				$ 1,400,000,000
Number of days out of 30 that common stock price exceeded conversion price						20 days
Convertible debt, threshold consecutive trading days						30 days
Convertible debt, threshold percentage of stock price trigger						130.00%
Percentage of conversion rate						0.98
Convertible debt, conversion ratio						0.011111
Convertible debt, conversion price (in dollars per share)						$ 90.00
Repurchase price as a percent of principal amount						100.00%
Holder of a percent of principal in event of default						25.00%
Percentage Trustee May Declare						100.00%
Percent Of Principal And Accrued Interest Due						100.00%
Shares Of Common Stock Covered By Note Hedges						13.9
Additional warrant transaction						2.1
Class of warrant or right, exercise price of warrants or rights (in dollars per share)						120
Stock repurchased during period, shares						19.2