Cash and Cash Equivalents (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Cash and Cash Equivalents [Abstract]
Available-for-sale Securities	$ 0us-gaap_AvailableForSaleSecurities	$ 0us-gaap_AvailableForSaleSecurities
Cash	601,000,000	364,700,000
Investments in cash equivalents	6,000,000
Restricted cash	1,444,000	1,446,000
Restricted cash outstanding, letters of credit used for collateral	1,000,000	1,000,000
Restricted cash guaranteed, investment certificate for collateral	100,000	100,000
Restricted cash and cash equivalents, foreign tender	$ 300,000	$ 300,000

Cash Aggregated in Cash and Cash Equivalents

No definition available.

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- Definition

Restricted Cash and Cash Equivalents, Foreign Tender

+ References

No definition available.

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- Definition

Restricted Cash Guaranteed Investment Certificate Used For Collateral

+ References

No definition available.

+ Details

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- Definition

Restricted Cash Outstanding Letters of Credit Used For Collateral

+ References

No definition available.

+ Details

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- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (aa)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

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- Definition

Other (not elsewhere specified in the taxonomy) short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

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- Definition

Cash and equivalents whose use in whole or in part is restricted for the long-term, generally by contractual agreements or regulatory requirements.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

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

+ Details

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