Fair Value of Financial Instruments (Details) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Liabilities
Derivative Liability	$ 4,128,000us-gaap_DerivativeLiabilities		$ 3,608,000us-gaap_DerivativeLiabilities
Recurring Basis
Assets
Money market funds	107,631,000		98,789,000
Derivative financial instruments	14,875,000		17,111,000
Liabilities
Derivative Liability	4,128,000		3,608,000
Transfer of assets from level 1 to level 2	0		0
Transfer of assets from level 2 to level 1	0		0
Transfer of liabilities from level 1 to level 2	0		0
Transfer of liabilities from level 2 to level 1	0		0
Transfer of assets into level 3	0	0
Transfer of assets out of level 3	0	0
Transfer of liabilities into level 3	0	0
Transfer of liabilities out of level 3	0	0
Recurring Basis \| Level 1
Assets
Money market funds	107,631,000		98,789,000
Derivative financial instruments	0		0
Demand deposits	78,600,000		70,000,000
Liabilities
Derivative Liability	0		0
Recurring Basis \| Level 2
Assets
Money market funds	0		0
Derivative financial instruments	14,875,000		17,111,000
Liabilities
Derivative Liability	$ 4,128,000		$ 3,608,000

This element represents demand deposits at fair value.

No definition available.

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- Definition

This element represents the fair value of investment in short-term money market instruments (such as commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and so forth), which are highly liquid (that is, readily convertible to known amounts of cash) and so near their maturity that they present an insignificant risk of changes in value because of changes in interest rates.

+ References

No definition available.

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- Definition

Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 45

-Paragraph 5

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- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

+ References

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-Publisher FASB

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- Definition

Amount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2.

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Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.

+ References

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Amount of transfers of liabilities measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2.

+ References

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Amount of transfers of liabilities measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.

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Amount of transfers of financial instrument classified as a liability into level 3 of the fair value hierarchy.

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Amount of transfers of financial instrument classified as a liability out of level 3 of the fair value hierarchy.

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Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

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Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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