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

12 Months Ended

Dec. 31, 2016

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
							2016	2015	2014
May 15, 2013	$	4,000	32.8	$	121.97	March 2015	—	2.7	21.4
December 4, 2014	$	3,000	18.0	$	166.70	March 2016	1.4	16.6	—
September 16, 2015	$	4,000	5.9	$	218.28		5.9	—	—
							7.3	19.3	21.4

⁽¹⁾  Includes commissions paid.