Treasury Stock (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Oct. 31, 2014	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount		$ 5,400,000,000		$ 5,400,000,000
Available to repurchase common stock		116,300,000		116,300,000
Amount used to repurchase stock				172,132,000	$ 1,500,998,000
Amount expended on share repurchases in open market transactions		$ 47,200,000	$ 0	$ 172,100,000	$ 0
Number of shares repurchased		711,385		2,693,500
Average per share price on share repurchases in open market transactions (in dollars per share)		$ 66.36		$ 63.91
Number of shares withheld to satisfy minimum tax withholding obligations		33,356	26,460	445,822	394,770
Payment for tax withholding related to vested stock units		$ 2,100,000	$ 1,600,000	$ 28,300,000	$ 22,800,000
Senior Notes Due 2019 [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchased during period, value			$ 1,500,000,000
Stock repurchased during the period, shares			1,700,000
Privately Negotiated Transaction [Member]
Equity, Class of Treasury Stock [Line Items]
Amount used to repurchase stock			$ 101,000,000
Purchase From Accelerated Share Repurchase [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchased during period, value			$ 1,400,000,000
Stock repurchased during the period, shares	2,600,000		21,800,000