Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Summary of Significant Accounting Policies [Abstract]

Allowance for Doubtful Accounts Activity

The following table presents our allowance for doubtful accounts activity for the periods indicated:

	For the Year Ended December 31,
	2016			2015			2014
Balance at beginning of period	$	12.1		$	13.9		$	7.5
Charged to costs and expenses		2.3			0.8			8.4
Deductions		(3.1	)		(2.6	)		(2.0	)
Balance at end of period	$	11.3		$	12.1		$	13.9

Environmental Reserves Activity

The following table presents the activity of our environmental reserves for the periods indicated:

	For the Year Ended December 31,
	2016			2015			2014
Balance at beginning of period	$	13.0		$	15.6		$	9.9
Charged to costs and expenses		7.0			6.4			11.9
Acquisition-related additions and other		0.5			1.1			2.5
Deductions		(8.6	)		(10.1	)		(8.7	)
Balance at end of period	$	11.9		$	13.0		$	15.6