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Statements of Cash Flow (Cash Flow Supplemental Disclosures) (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended
--- | ---
Mar. 31, 2012 | Mar. 31, 2011
Supplemental Cash Flow Information [Abstract] |  |
Interest | $ 2,111 | $ 1,969
Federal income tax | $ 0 | $ 173

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- Definition The amount of cash paid during the current period to federal authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of federal taxes. + References No definition available. + Details
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- Definition The amount of cash paid for interest during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 29 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 230 -SubTopic 10 -Section 45 -Paragraph 25 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3536-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4297-108586 + Details
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