Derivative Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2017

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of the gross fair values of derivatives on balance sheet

For additional information on derivative fair values, see Note 7—Fair Value Measurements.



	March 31, 2017			December 31, 2016
	(in millions)
Derivative Assets
Unrealized gains in other current assets	$	1.9		$	7.9
Unrealized gains in other assets	—			1.1
Total derivative assets	1.9			9.0
Derivative Liabilities
Unrealized losses in other current liabilities	(0.5		)	—
Unrealized losses in other liabilities	(2.0		)	(1.6		)
Total derivative liabilities	(2.5		)	(1.6		)
Net derivative (liabilities) assets	$	(0.6	)	$	7.4

Schedule of effects of derivatives in consolidated statements of operations

The effect of derivatives in our consolidated statements of operations is shown below. All amounts arise from natural gas derivatives that are not designated as hedging instruments and are recorded in cost of goods sold.



	Three months ended March 31,
	2017			2016
	(in millions)
Unrealized net mark-to-market losses	$	(7.9	)	$	(2.3	)
Realized net gains (losses)	0.3			(7.4		)
Net derivative losses	$	(7.6	)	$	(9.7	)

Schedule of offsetting of derivative assets and liabilities

The following table presents amounts relevant to offsetting our derivative assets and liabilities as of March 31, 2017 and December 31, 2016:



	Gross and net amounts presented in consolidated balance sheets⁽¹⁾			Gross amounts not offset in consolidated balance sheets
				Financial instruments			Cash collateral received (pledged)		Net amount
	(in millions)
March 31, 2017
Total derivative assets	$	1.9		$	1.9		$	—	$	—
Total derivative liabilities	(2.5		)	(1.9		)	—		(0.6		)
Net derivative liabilities	$	(0.6	)	$	—		$	—	$	(0.6	)
December 31, 2016
Total derivative assets	$	9.0		$	1.6		$	—	$	7.4
Total derivative liabilities	(1.6		)	(1.6		)	—		—
Net derivative assets	$	7.4		$	—		$	—	$	7.4

_______________________________________________________________________________


⁽¹⁾	We report the fair values of our derivative assets and liabilities on a gross basis on our consolidated balance sheets. As a result, the gross amounts recognized and net amounts presented herein are the same.