Debt (Senior Secured Credit Facilities) (Details) (USD $)	1 Months Ended	12 Months Ended
	Oct. 31, 2014	Mar. 31, 2015
Line of Credit Facility [Line Items]
Aggregate principal amount (more than)	$ 100,000,000
ABL Facility [Member]
Line of Credit Facility [Line Items]
Debt term		5 years
Current borrowing capacity		1,200,000,000
Potential additional borrowing capacity		500,000,000
ABL Revolver [Member]
Line of Credit Facility [Line Items]
Debt term	5 years
Current borrowing capacity	1,200,000,000.0
Potential additional borrowing capacity	500,000,000
Description of variable rate basis	LIBOR
Maximum borrowing capacity	1,000,000,000.0
Debt covenant, minimum fixed charge coverage ratio	1.25
Covenant, minimum amount for excess availability under ABL Revolver	110,000,000
Covenant, percentage applied on lesser of ABL Revolver commitment and applicable borrowing base	12.50%
Number of days preceding maturity date	90 days
Percentage of the lesser of total revolver commitment to applicable borrowing base	20.00%
ABL Revolver [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Percentage of the lesser of total revolver commitment to applicable borrowing base	25.00%
ABL Revolver [Member] | LIBOR [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.50%
ABL Revolver [Member] | LIBOR [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.00%
ABL Revolver [Member] | Prime Rate [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.50%
ABL Revolver [Member] | Prime Rate [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.00%
Four-year Secured Term Loan Credit Facility [Member]
Line of Credit Facility [Line Items]
Principal amount		$ 1,700,000,000.0
Debt term		4 years
Floating Rate Term Loan Facility Due March 2017 [Member] | ABL Facility [Member]
Line of Credit Facility [Line Items]
Interest rate, floor		1.00%
Floating Rate Term Loan Facility Due March 2017 [Member] | ABL Facility [Member] | LIBOR [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Basis spread on variable rate		2.75%