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Capital Stock, Dividends and Common Stock Repurchase Program (Detail) $ / shares in Units, shares in Thousands, $ in Millions	2 Months Ended	12 Months Ended
	Feb. 14, 2019 USD ($)	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) item $ / shares shares
Accelerated Share Repurchases [Line Items]
Cash paid for repurchase of common stock		$ 402	$ 248	$ 1,004
Shares repurchased (in shares) | shares		3,687	2,247	11,673
Weighted average per share purchase price | $ / shares		$ 108.92	$ 108.60	$ 86.35
Total repurchases		$ 402	$ 244	$ 1,008
Authorized share repurchases		1,350
Accelerated Share Repurchase Agreement (ASR) [Member]
Accelerated Share Repurchases [Line Items]
Cash paid for repurchase of common stock		$ 313	$ 180	$ 850
Shares repurchased (in shares) | shares		2,800	1,600	9,800
Number of ASR agreements | item				4
10b5-1 Plan [Member]
Accelerated Share Repurchases [Line Items]
Cash paid for repurchase of common stock	$ 4	$ 89	$ 64	$ 158
Shares repurchased (in shares) | shares		900	700	1,900

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- Definition

Final price paid per share for the purchase of the targeted number of shares, determined by an average market price over a fixed period of time.

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The cash outflow to reacquire common stock during the period.

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Number of shares that have been repurchased during the period and are being held in treasury.

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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