Earnings per Common Share (Tables)

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Computation of Basic and Diluted Earnings per Share

The following table sets forth the computation of basic and diluted earnings per common share:

Year Ended December 31,	2017		2016		2015
Net income, basic and diluted	$	106.5	$	95.6	$	86.8
Weighted average common shares outstanding for basic earnings per share computation	51,429,366		44,511,774		45,184,091
Dilutive effects of stock-based compensation	473,843		398,622		462,327
Weighted average common shares outstanding for diluted earnings per common share computation	51,903,209		44,910,396		45,646,418
Basic earnings per common share	$	2.07	$	2.15	$	1.92
Diluted earnings per common share	2.05		2.13		1.90