Employee Benefit Plans (Expected future benefit payments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
Defined Benefit Plan, Expected Future Benefit Payments in Year One	$ 3,804
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	4,454
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	4,584
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	4,503
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	4,823
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	$ 32,055

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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