Capital Stock (Tables)

12 Months Ended

Dec. 31, 2016

Equity [Abstract]

Stock Repurchases Pursuant To Board Of Director Authorizations

The remaining repurchases were made pursuant to the following authorizations (in millions of shares):

	Shares Repurchased			Authorization Remaining at December 31, 2016
Board of Directors’ Authorization	2016	2015	2014
1997 Authorization	—	0.9	3.2	—
2007 Authorization	—	0.9	5.8	—
2014 Authorization	—	20.0	—	—
2015 Authorization	9.0	6.0	—	—
2016 Authorization	0.7	—	—	19.3
Total	9.7	27.8	9.0	19.3