Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

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,
	2015			2014			2013
Balance at beginning of period	$	13.9		$	7.5		$	13.2
Charged to costs and expenses		0.8			8.4			2.1
Deductions		(2.6	)		(2.0	)		(7.8	)
Balance at end of period	$	12.1		$	13.9		$	7.5

Environmental Reserves Activity

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

	For the Year Ended December 31,
	2015			2014			2013
Balance at beginning of period	$	15.6		$	9.9		$	13.7
Charged to costs and expenses		6.4			11.9			3.9
Acquisition-related additions and other		1.1			2.5			0.7
Deductions		(10.1	)		(8.7	)		(8.4	)
Balance at end of period	$	13.0		$	15.6		$	9.9