Stockholders' Equity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stockholders' Equity, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock, shares authorized	100,000	100,000
Preferred stock, par value per share	$ 100	$ 100
Common stock, shares authorized	500,000,000	500,000,000
Common stock, par value per share	$ 1.00	$ 1.00
Common stock, shares issued	256,537,535	256,112,943
Number of treasury shares held	101,109,186	101,109,186
Share Repurchases [Line Items]
Document Fiscal Year Focus	2016
Payments for Repurchase of Common Stock	$ 0	$ 600,164,000	$ 601,077,000
November 2012 Authorization [Member]
Share Repurchases [Line Items]
Authorized dollar amount for share repurchase program	$ 1,000,000,000
Payments for Repurchase of Common Stock		$ 292,565,000
Shares repurchased		3,596,980
Average price per share for repurchased shares (in dollars per share)		$ 81.06
January 2015 Authorization [Member]
Share Repurchases [Line Items]
Number of shares authorized to be repurchased	15,000,000
Payments for Repurchase of Common Stock		$ 600,164,000
Shares repurchased		8,228,542
Average price per share for repurchased shares (in dollars per share)		$ 72.94
Remaining number of shares authorized to be repurchased	6,771,458
May 2012 Authorization [Member]
Share Repurchases [Line Items]
Number of shares authorized to be repurchased	10,000,000
Payments for Repurchase of Common Stock			$ 308,512
Shares repurchased			3,870,248
Average price per share for repurchased shares (in dollars per share)			$ 79.71