Earnings Per Share, Share Repurchases and Dividends on Common Stock (Tables)

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Share Repurchases

The table below summarizes the company’s share repurchases to date under the authorizations described above:

Repurchase Program Authorization Date	Amount Authorized (in millions)		Total Shares Retired (in millions)	Average  Price Per Share(1)		Date Completed	Shares Repurchased (in millions)
							Year Ended December 31
							2020	2019	2018
September 16, 2015	$	4,000	15.4	$	260.33	March 2020	0.9	3.2	3.8
December 4, 2018	$	3,000	0.5	$	326.20		0.5	—	—
							1.4	3.2	3.8

(1)Includes commissions paid.