Debt (Narrative) (Details) (USD $)		9 Months Ended		9 Months Ended										9 Months Ended
	Jul. 25, 2012 Inventory Sublimit [Member]	Sep. 30, 2012 Senior Secured Credit Facility [Member]	Jul. 25, 2012 Senior Secured Credit Facility [Member]	Sep. 30, 2012 Senior Unsecured Notes [Member]	Jul. 25, 2012 Accordion Feature [Member]	Sep. 30, 2012 Senior Unsecured Notes [Member]	Feb. 01, 2012 Senior Unsecured Notes [Member]	Sep. 30, 2012 Senior Secured Credit Facility [Member]	Sep. 30, 2012 Senior Secured Credit Facility [Member] Letters Of Credit [Member]	Sep. 30, 2012 Inventory Sublimit [Member] Senior Secured Credit Facility [Member]	Sep. 30, 2012 Senior Secured Credit Facility [Member]	Sep. 30, 2012 Inventory Sublimit [Member]	Jul. 25, 2012 Amended Facility [Member]	Sep. 30, 2012 Minimum [Member]	Sep. 30, 2012 Maximum [Member]	Jul. 25, 2012 Accordion Feature [Member]
Debt Instrument [Line Items]
Credit facility, amount outstanding								$ 483,000,000		$ 48,600,000
Credit facility, maximum borrowing capacity	125,000,000		775,000,000		225,000,000				100,000,000			150,000,000	1,000,000,000			300,000,000
Credit facility, aggregate maximum borrowing capacity											1,300,000,000
Letters of credit, outstanding amount									12,600,000
Credit facility and senior unsecured notes, maturity dates		Jul. 25, 2017		Dec. 15, 2018
Eurodollar Borrowings Margin														1.75%	2.75%
Alternate Base Rate Borrowings Margin														0.75%	1.75%
Letter of Credit, Fee Percentage														1.75%	2.75%
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage														0.375%	0.50%
Total amount available for borrowings under credit facility								504,400,000
Senior unsecured notes, principal amount						$ 350,000,000	$ 100,000,000
Senior unsecured notes, stated rate						7.875%
Senior unsecured notes, percentage of face value							101.00%
Senior unsecured notes, effective interest rate							7.682%