Employee Benefit Plans Future Benefit Payments (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	$ 13,338
2013	33,810
2014	17,977
2015	10,397
2016	9,966
2017 — 2021	46,078
Postretirement Medical [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	656
2013	656
2014	659
2015	662
2016	664
2017 — 2021	$ 3,369

The amount of the aggregate benefits expected to be paid in the five fiscal years thereafter (the aggregate amount of benefits expected to be paid in years 6 through 10 after the date of the latest statement of financial position).

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 132R

-Paragraph 5

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=6962843&loc=d3e1928-114920

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant