Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Basic and Diluted Loss Per Share

The following table provides a reconciliation of the data used in the calculation of basic and diluted common shares outstanding for the three years ended December 31, 2017, 2016 and 2015.

	2017	2016	2015
Basic weighted average common shares outstanding	88.3	89.2	89.8
Add: Dilutive impact of outstanding equity awards	0.7	0.7	0.9
Diluted weighted average common shares outstanding	89.0	89.9	90.7

Number of Shares Underlying Stock Options Excluded from Computation of Diluted Loss

The following table provides the number of shares underlying stock options excluded from the computation of diluted earnings per share for the three years ended December 31, 2017, 2016 and 2015 because they were anti-dilutive.

	2017		2016		2015
Anti-dilutive stock options	0.3		0.7		0.4
Average exercise price	$	42.43	$	38.34	$	42.50
Year(s) of expiration	2024 - 2025		2024 - 2026		2024 - 2025