The cash inflow associated with the sale of investments that are pledged or subject to withdrawal restrictions during the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 15, 16
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3179-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Name:	us-gaap_ProceedsFromSaleOfRestrictedInvestments
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Investments (Details) (USD $) In Thousands	1 Months Ended	3 Months Ended	6 Months Ended
Investments (Details) (USD $) In Thousands	Jan. 31, 2010	Jun. 30, 2011	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Investments (Textuals) [Abstract]
Auction Rate Securities call value	$ 9,456
Gain on sale of auction rate securities				425
Long-term restricted investments		3,146	3,146		3,396
Obligations under letters of credit liquidated		$ 250	$ 250