Subsequent Event (Details) (ABL Facility, maturity July 6, 2013, USD $) In Millions, unless otherwise specified	12 Months Ended	1 Months Ended
Feb. 03, 2012	Apr. 06, 2012 ABL Facility amended and restated	Apr. 06, 2012 ABL Facility amended and restated LIBOR loans	Apr. 06, 2012 ABL Facility amended and restated Base-rate Loans
Subsequent Event
Maximum financing under credit agreements	$ 1,031	$ 1,200
Letters of credit, amount available	$ 350.0	$ 350.0
Spread on variable rate (as a percent)			1.75%	0.75%
Commitment fees (as a percent)	0.375%	0.375%

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant