Employee Benefit Plans, 401(k) plan and Deferred Compensation Plan (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Benefit Textuals [Abstract]
Employee Contribution Matched in Percent	30.00%
Matching Contributions to Plan	$ 20.2	$ 20.7	$ 20.2
NQDC [Member]
Employee Benefit Textuals [Abstract]
Deferred Compensation Liability	$ 16.3	$ 15.4

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Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable within one year (or the operating cycle, if longer). Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 710

-SubTopic 10

-Section 30

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6409875&loc=d3e20028-108363

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 710

-SubTopic 10

-Section 25

-Paragraph 9

-URI http://asc.fasb.org/extlink&oid=6409733&loc=d3e19512-108361

+ Details

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- Definition

The increase in the fair value of plan assets from contributions made by the employer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

+ Details

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

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- Details

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