Stockholders' Equity (Narrative) (Details) - USD ($)
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1 Months Ended |
12 Months Ended |
|
|
Mar. 31, 2018 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Nov. 30, 2017 |
Nov. 30, 2015 |
| Stockholders' Equity [Line Items] |
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| Available outstanding common stock under repurchase programs |
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$ 1,500,000,000
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|
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|
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| Additional paid-in capital |
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0
|
$ 0
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|
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| Share repurchases recorded as a reduction to retained earnings |
|
$ 1,418,000,000
|
$ 885,000,000
|
$ 996,000,000
|
|
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| Percentage Of Change In Dividends Paid Per Share |
8.80%
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|
|
|
|
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| Dividends declared per share |
|
$ 3.47
|
$ 3.19
|
$ 2.93
|
|
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| Deferred Tax Liabilities, Other |
|
|
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$ 30,000,000
|
|
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| November Two Thousand Fifteen Board of Directors Authorization [Member] |
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| Stockholders' Equity [Line Items] |
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| Stock Repurchase Program, Authorized Amount |
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|
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$ 2,000,000,000.0
|
| November Two Thousand Seventeen Board of Directors Authorization [Member] |
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| Stockholders' Equity [Line Items] |
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| Stock Repurchase Program, Authorized Amount |
|
|
|
|
$ 2,000,000,000.0
|
|
| Retained Earnings [Member] |
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|
|
|
|
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| Stockholders' Equity [Line Items] |
|
|
|
|
|
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| Share repurchases recorded as a reduction to retained earnings |
|
$ 1,250,000,000
|
$ 724,000,000
|
435,000,000
|
|
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| Reduction to retained earnings, before tax, related to the acquisition of RCCS LLC |
|
|
|
167,000,000
|
|
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| Reduction to retained earnings, after tax, related to the acquisition of RCCS LLC |
|
|
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$ 197,000,000
|
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