Summary of Significant Accounting Policies - Life Insurance Policies (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Gross cash surrender value of life insurance	$ 27.6	$ 26.2
Loan on cash surrender value of life insurance	23.1	23.1
Net cash surrender value of life insurance	4.5	3.1
Gross death benefit of life insurance contracts	38.8
Life insurance proceeds to be received upon the death of participants	15.1
Life insurance gain to be recognized upon death of participants	$ 11.2

Cash Surrender Value of Life Insurance, Gain to be Recognized Upon Death of Participant

No definition available.

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- Definition

Cash surrender value of life insurance gross.

+ References

No definition available.

+ Details

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- Definition

Loan on cash surrender value of life insurance.

+ References

No definition available.

+ Details

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- Details

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- Definition

Carrying amount as of the balance sheet date of amounts which could be received based on the terms of the insurance contract upon surrendering life policies owned by the entity.

+ 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 210.5-02.17)

-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 17

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 4

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6812-107765

+ Details

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- Definition

This item represents the amount that could be realized under a life insurance contract or contracts owned by the Entity as of the date of the statement of financial position. Such Entity-owned life insurance policies are commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

+ 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 210.5-02.12)

-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 12

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 325

-SubTopic 30

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6384206&loc=d3e41899-111602

+ Details

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- Definition

Face value (death benefits) of the life insurance policies underlying the life settlement contracts accounted for under the fair value method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Life Settlement Contract

-URI http://asc.fasb.org/extlink&oid=6516907

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 325

-SubTopic 30

-Section 50

-Paragraph 8

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6385267&loc=d3e42732-111610

+ Details

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