Commitments And Contingencies (Details) (USD $)	3 Months Ended
Mar. 31, 2012	Dec. 31, 2011
Commitments And Contingencies [Abstract]
Self insurance deductible for workers compensation	$ 750,000
Self insurance deductible for general liability	750,000
Self insurance deductible for medical and dental	250,000
Self-insured risk accruals	20,000,000	19,700,000
Net receivable for medical and dental coverage	$ 36,000	$ 1,000

Carrying amount (including both current and noncurrent portions) of accrued known and estimated losses incurred as of the balance sheet date for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.24)

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

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