Stockholders' Equity (Details) - USD ($)	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	May 22, 2018
Stockholders' Equity, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock, shares authorized	100,000		100,000	100,000
Preferred stock, par value per share	$ 100		$ 100	$ 100
Common stock, shares authorized	500,000,000		500,000,000	500,000,000
Common stock, par value per share	$ 1.00		$ 1.00	$ 1.00
Common stock, shares issued	257,822,352		258,551,748	257,822,352
Number of treasury shares held	112,905,810		114,249,432	112,905,810
Share Repurchases [Line Items]
Accelerated Share Repurchases, Settlement (Payment) or Receipt						$ 700,000,000
Payments for Repurchase of Common Stock			$ 143,280,000	$ 894,977,000	$ 105,023,000
January 2015 Authorization [Member]
Share Repurchases [Line Items]
Shares repurchased				440,608
Payments for Repurchase of Common Stock				$ 44,977,000
Average price per share for repurchased shares (in dollars per share)				$ 102.08
Remaining number of shares authorized to be repurchased	5,271,168			5,271,168
February 2018 Authorization [Member]
Share Repurchases [Line Items]
Shares repurchased			1,343,622	1,753,768
Number of shares authorized to be repurchased	20,000,000			20,000,000
Accelerated Shares Repurchased	1,463,815	7,078,751		8,542,566
Accelerated Share Repurchases, Final Price Paid Per Share				$ 81.94
Payments for Repurchase of Common Stock			$ 143,280,000	$ 150,000,000
Average price per share for repurchased shares (in dollars per share)			$ 106.64	$ 85.53
Remaining number of shares authorized to be repurchased			8,360,044