Subsidiary Guarantors (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2011	Dec. 31, 2010
$250 million 6 3/4% senior subordinated notes due March 2015
Long-term Debt
Principal amount of long-term debt	$ 250	$ 250
Debt instrument interest rate stated percentage (as a percent)	6.75%	6.75%
$325 million 8 3/4% senior subordinated notes due August 2019
Long-term Debt
Principal amount of long-term debt	$ 325	$ 325
Debt instrument interest rate stated percentage (as a percent)	8.75%	8.75%

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 21
-Paragraph 16, 20
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant