Consolidated Statements of Comprehensive Income (Parentheticals) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Auction Rate Securities [Member]
Change in unrealized losses on securities, tax	$ 0	$ 0	$ 0
Available-for-sale Securities [Member]
Change in unrealized losses on securities, tax	$ 0	$ 0	$ 0

Amount of tax expense (benefit), after reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

Reference 1: 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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e640-108580

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