Investments (Narrative) (Details) (USD $)	3 Months Ended
Mar. 31, 2012	Mar. 26, 2011	Dec. 31, 2011
Investments [Abstract]
Total realized gains on sales of AFS securities	$ 2,549,000	$ 9,260,000
Total realized losses on sales of AFS securities	2,311,000	1,227,000
Number of AFS securities issues contributing to the total unrealized loss	295
Total unrealized losses	$ 12,764,000		$ 19,357,000

This element represents the amount of loss recognized for other than temporary impairments (OTTI) of investments in debt and equity securities.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 320

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 5.M)

-URI http://asc.fasb.org/extlink&oid=6784337&loc=d3e87990-122713

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration