Long-Term Debt To Affiliated Trusts (Schedule Of Distribution Rates Paid) (Details)	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 1998
Long-Term Debt To Affiliated Trusts [Abstract]
Low distribution rate	1.11%	1.10%	1.11%
High distribution rate	1.29%	1.11%	1.19%
Distribution rate at the end of the year	1.29%	1.11%	1.11%	8.45%

Long-Term Debt To Affiliated Trusts [Abstract]

No definition available.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

Maximum contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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- Definition

Minimum contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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