Derivative Contracts (Tables)

6 Months Ended

Jun. 30, 2015

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Summary of Outstanding Commodity Derivative Contracts

The following tables provide a summary of our outstanding commodity derivative contracts:

(in millions, except for number of contracts)
	As of
	June 30, 2015			December 31, 2014			June 30, 2014
	Net Notional Amount		# of Contracts	Net Notional Amount		# of Contracts	Net Notional Amount		# of Contracts
Metal	$	13.3	585	$	13.4	400	$	12.6	421
Natural Gas	2.2		68	2.6		78	2.7		73
Electricity	2.5		35	5.9		77	2.7		38
Total	$	18.0	688	$	21.9	555	$	18.0	532

	As of
(in millions)	June 30, 2015			December 31, 2014			June 30, 2014
Notional Amount - Long	$	31.5		$	29.9		$	27.9
Notional Amount - Short	(13.5		)	(8.0		)	(9.9		)
Total	$	18.0		$	21.9		$	18.0

Effects of Derivative Contracts in Condensed Consolidated Financial Statements

The following tables summarize the gross amounts of open derivative contracts, the net amounts presented in the consolidated balance sheets, and the collateral deposited with counterparties:

(in millions)	As of June 30, 2015
	Gross Amounts of Recognized Assets		Gross Amounts Offset in Consolidated Balance Sheet			Net Amounts of Assets Presented in Consolidated Balance Sheet
Metal	$	1.4	$	(1.4	)	$	—
Natural gas	—		—			—
Electricity	—		—			—
Collateral on deposit	2.8		(1.1		)	1.7
Total	$	4.2	$	(2.5	)	$	1.7
Consolidated balance sheet location:
Prepaid expenses and other current assets						$	1.7
Total						$	1.7

(in millions)	As of June 30, 2015
	Gross Amounts of Recognized Liabilities		Gross Amounts Offset in Consolidated Balance Sheet			Net Amounts of Liabilities Presented in Consolidated Balance Sheet
Metal	$	1.7	$	(1.7	)	$	—
Natural gas	0.4		(0.4		)	—
Electricity	0.4		(0.4		)	—
Total	$	2.5	$	(2.5	)	$	—

(in millions)	As of December 31, 2014
	Gross Amounts of Recognized Assets		Gross Amounts Offset in Consolidated Balance Sheet			Net Amounts of Assets Presented in Consolidated Balance Sheet
Metal	$	0.5	$	(0.5	)	$	—
Natural gas	—		—			—
Electricity	0.2		(0.2		)	—
Collateral on deposit	3.3		(2.0		)	1.3
Total	$	4.0	$	(2.7	)	$	1.3
Consolidated balance sheet location:
Prepaid expenses and other current assets						$	1.3
Total						$	1.3

(in millions)	As of December 31, 2014
	Gross Amounts of Recognized Liabilities		Gross Amounts Offset in Consolidated Balance Sheet			Net Amounts of Liabilities Presented in Consolidated Balance Sheet
Metal	$	1.4	$	(1.4	)	$	—
Natural gas	0.7		(0.7		)	—
Electricity	0.6		(0.6		)	—
Total	$	2.7	$	(2.7	)	$	—

(in millions)	As of June 30, 2014
	Gross Amounts of Recognized Assets		Gross Amounts Offset in Consolidated Balance Sheet			Net Amounts of Assets Presented in Consolidated Balance Sheet
Metal	$	0.9	$	(0.8	)	$	0.1
Natural gas	0.1		—			0.1
Electricity	0.4		(0.1		)	0.3
Collateral on deposit	1.0		—			1.0
Total	$	2.4	$	(0.9	)	$	1.5
Consolidated balance sheet location:
Prepaid expenses and other current assets						$	1.5
Total						$	1.5

(in millions)	As of June 30, 2014
	Gross Amounts of Recognized Liabilities		Gross Amounts Offset in Consolidated Balance Sheet			Net Amounts of Liabilities Presented in Consolidated Balance Sheet
Metal	$	0.8	$	(0.8	)	$	—
Natural gas	—		—			—
Electricity	0.1		(0.1		)	—
Total	$	0.9	$	(0.9	)	$	—

The following table summarizes the effects of derivative contracts in the consolidated statements of operations:

(in millions)	Three Months Ended June 30,					Six Months Ended June 30,
	2015		2014			2015			2014
Losses (gains) in cost of sales for:
Metal	$	0.4	$	(0.6	)	$	(0.1	)	$	(0.5	)
Natural gas	—		—			0.1			(0.2		)
Electricity	0.3		(0.2		)	0.3			(1.6		)
Total	$	0.7	$	(0.8	)	$	0.3		$	(2.3	)