Available for sale securities contractual maturity period.

No definition available.

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- Definition

Available for sale securities unrealized loss position percentage of total fair value.

+ References

No definition available.

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- Definition

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a recurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

+ References

No definition available.

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- Definition

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

+ References

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

-Publisher FASB

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-Topic 320

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-Section 50

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- Definition

The carrying amount of securities categorized neither as held-to-maturity nor trading which serve as security for borrowings or other arrangements.

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

-Publisher FASB

-Name Accounting Standards Codification

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-Name Regulation S-X (SX)

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- Definition

Carrying amount as of the balance sheet date of cash collateral held for borrowed securities, for which the cash is restricted as to withdrawal or usage.

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-Publisher FASB

-Name Accounting Standards Codification

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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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-Publisher FASB

-Name Accounting Standards Codification

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Fair value portion of notes payable.

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-Name Accounting Standards Codification

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Marketable Securities and Fair Value Measurements - Additional Information (Details) - USD ($)	6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Available-for-sale marketable securities	$ 50,500,000
Cash Collateral	32,400,000
Assets, fair value	52,840,000		$ 52,907,000
Realized gains or losses	$ 0	$ 0
Percentage of total fair value of available for sale securities in unrealized loss position	0.00%		59.00%
Transfers between Level I and Level II assets	$ 0		$ 0
Level II
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value			1,000
Carrying value of notes payable	509,700,000		544,900,000
Certificates of Deposit
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	2,318,000		2,318,000
U.S. Treasuries
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Assets, fair value	$ 50,015,000		$ 50,082,000
U.S. Treasuries \| Minimum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Contractual maturities	2 years		2 years
U.S. Treasuries \| Maximum
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Contractual maturities	3 years		3 years