Fair Value Measurements (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Fair Value Measurements (Details) [Line Items]
Auction Rate Securities, Noncurrent	$ 1,900,000
Two Municipal Auction Rate Securities [Member]
Fair Value Measurements (Details) [Line Items]
Auction Rate Securities, Noncurrent	1,500,000	1,600,000
Auction Rate Securities [Member]
Fair Value Measurements (Details) [Line Items]
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax	$ 350,000

Accumulated appreciation or loss, net of tax, in value of the total of available-for-sale securities at the end of an accounting period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14A

-URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669686-108580

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e637-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e681-108580

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 10A

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669646-108580

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