Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions								1 Months Ended	3 Months Ended			12 Months Ended
	Feb. 06, 2019	Feb. 05, 2019	Feb. 06, 2018	Feb. 05, 2018	Feb. 01, 2017	Jan. 31, 2017	Jan. 15, 2014	Jul. 31, 2016	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Dividends declared per common share												$ 0.72	$ 0.62	$ 0.54
Preferred Stock, Par or Stated Value Per Share												$ 100	$ 100
Treasury Stock, Shares, Acquired													84,400,000	197,100,000
Treasury Stock, Value, Acquired												$ 2,230	$ 2,448	$ 4,244
Payments for Repurchase of Common Stock												2,227	$ 2,452	$ 4,227
Open Market [Member]
Treasury Stock, Shares, Acquired													50,100,000
Treasury Stock, Value, Acquired													$ 1,400
The 2015 Repurchase Program [Member]
Treasury Stock, Shares, Acquired														110,000,000
Treasury Stock, Value, Acquired														$ 2,200
The 2016 ASR Agreement [Member]
Treasury Stock, Shares, Acquired								74,400,000			12,300,000			86,700,000
Treasury Stock, Value, Acquired								$ 2,000
The 2016 Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount											$ 4,000			$ 4,000
The 2017 ASR Agreement [Member]
Treasury Stock, Shares, Acquired									17,200,000	17,100,000
Payments for Repurchase of Common Stock									$ 500	$ 500
The 2018 Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount												$ 2,000
The 2016 and 2018 Repurchase Program [Member]
Treasury Stock, Shares, Acquired												74,800,000
Payments for Repurchase of Common Stock												$ 2,200
Common Stock [Member]
Percentage increase of dvidend declared			16.10%		14.80%
Dividends declared per common share			$ 0.18	$ 0.155	$ 0.155	$ 0.135
Convertible Preferred Stock, Shares Issued upon Conversion							50,000
Convertible Preferred Stock, Threshold Trading Days							25 days
Convertible Preferred Stock, Threshold Consecutive Trading Days							40 days
Minimum Closing Price of Common Stock for the Company to Exercise Option to Convert Preferred Stock							$ 35
Common Stock [Member] | Subsequent Event [Member]
Percentage increase of dvidend declared	11.10%
Dividends declared per common share	$ 0.20	$ 0.18
Series A Convertible Preferred Stock [Member]
Preferred Stock, Dividend Rate, Percentage							4.25%
Series A Convertible Preferred Stock [Member] | Samsung Corning Precision Materials Co., Ltd. [Member]
Preferred Stock, Par or Stated Value Per Share							$ 100
Stock Issued During Period, Shares, Acquisitions							1,900
Share Price							$ 1,000,000
Stock Issued During Period, Value, Acquisitions							$ 1,900
Stock Issued During Period, Value, New Issues							$ 400