Long-term Debt (Details 3) ($325 million 8 3/4% senior subordinated notes due August 2019, USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013
$325 million 8 3/4% senior subordinated notes due August 2019
Long-term Debt
Principal amount of long-term debt	$ 325
Debt instrument interest rate stated percentage	8.75%

Increase of additional borrowings on existing and new debt instruments.

Reference 1: 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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph f

-Article 4

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