Subsequent Events (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Subsequent Event [Line Items]
Long-term Debt, Gross	$ 4,178.4	$ 4,178.2
Recourse Fixed Rate Debt Unsecured Twenty One [Member]
Subsequent Event [Line Items]
Long-term Debt, Gross	$ 0.0	100.0
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.70%
Recourse Fixed Rate Debt Unsecured Twenty Two [Member]
Subsequent Event [Line Items]
Long-term Debt, Gross	$ 0.0	250.0
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	4.75%
Recourse Fixed Rate Debt Unsecured Twenty Three [Member]
Subsequent Event [Line Items]
Long-term Debt, Gross	$ 0.0	$ 70.0
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	5.75%

Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

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)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 9

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- Definition

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate.

+ References

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- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

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