BASIC AND DILUTED EARNINGS PER COMMON SHARE - Components of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Numerator:
Income from continuing operations, net of taxes	$ 10.8	$ 26.0	$ 21.4	$ 25.2
Loss from discontinued operations, net of taxes	(2.5)	0.0	(2.1)	(0.1)
Net income	$ 8.3	$ 26.0	$ 19.3	$ 25.1	[1]
Denominator:
Weighted average common shares outstanding - Basic (shares)	52,515,869	52,440,580	52,499,141	52,413,552
Effect of dilutive restricted stock (shares)	76,499	169,225	121,925	174,316
Weighted average common shares outstanding - Diluted (shares)	52,592,368	52,609,805	52,621,066	52,587,868
Basic earnings per common share:
Continuing operations (usd per share)	$ 0.21	$ 0.50	$ 0.41	$ 0.48
Discontinued operations (usd per share)	(0.05)	0.00	(0.04)	0.00
Net income (loss) (usd per share)	0.16	0.50	0.37	0.48
Diluted earnings per common share:
Continuing operations (usd per share)	0.21	0.49	0.41	0.48
Discontinued operations (usd per share)	(0.05)	0.00	(0.04)	0.00
Net income (loss) (usd per share)	$ 0.16	$ 0.49	$ 0.37	$ 0.48

[1] Adjusted as a result of the adoption of certain accounting pronouncements beginning on January 1, 2016. See Note 1, "Description of Business and Summary of Significant Accounting Policies - Recently Adopted Accounting Pronouncements" for details of these adjustments.