Earnings Per Share, Share Repurchases and Dividends on Common Stock (Unaudited) (Details 2) - $ / shares shares in Millions	1 Months Ended	3 Months Ended
May 31, 2018	Jan. 31, 2018	May 31, 2017	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share, Basic and Diluted [Abstract]
Dilutive effect of of stock awards and options granted to employees under stock-based compensation plans				0.7	1.1
Common stock dividends per share, declared (in dollars per share)	$ 1.20	$ 1.10	$ 1.00	$ 1.20	$ 1.10
Increase in quarterly common stock dividend (percent)	9.00%	10.00%

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 28A
-URI http://asc.fasb.org/extlink&oid=109260490&loc=d3e1500-109256

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

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Period Type:	duration