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

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

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Topic 210
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Summary of Significant Accounting Policies (Recently Adopted and Issued Accounting Pronouncements) (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Jan. 31, 2009
Long-term Debt [Member] \| Accounting Standards Update 2015-03 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unamortized debt issuance costs		$ 0.1
Deferred Charges and Other Assets [Member] \| Accounting Standards Update 2015-03 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unamortized debt issuance costs		$ (0.1)
7.25% Unsecured Notes due February 1, 2019 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unamortized debt issuance costs	$ 0.1
Interest rate of debt instrument	7.25%	7.25%	7.25%