Supplemental Guarantor and Non-Guarantor Financial Information (Details) (9.875% senior notes, USD $) In Millions, unless otherwise specified	0 Months Ended
Nov. 21, 2012	Dec. 31, 2012
9.875% senior notes
Debt instrument
Amount borrowed	$ 500.0
Interest rate (as a percent)	9.875%	9.875%

Increase for additional borrowings on the debt instrument during the period.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 4

-Section 08

-Paragraph f

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(f))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Name:	us-gaap_DebtInstrumentIncreaseAdditionalBorrowings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration